BIOLOGY 

LIBRAftY 

G 


APPLIED    BACTERIOLOGY 
FOR  NURSES 


BY 

CHARLES  F.   BOLDUAN,   M.  D. 

DIRECTOR,   BUREAU  OF   PUBLIC  HEALTH   EDUCATION,  DEPARTMENT 
OF  HEALTH,   CITY   OF   NEW   YORK 


MARIE  GRUND,   M.  D. 

BACTERIOLOGIST,   RESEARCH   LABORATORY,  DEPARTMENT  OF 
HEALTH,   CITY   OF  NEW  YORK 


SECOND  EDITION,  THOROUGHLY  REVISED 


PHILADELPHIA  AND  LONDON 

W.    B.    SAUNDERS    COMPANY 
1918 


BIOLOGY 

LIBRARY 

G 


Copyright,  1913.  by  W.  B.  Saunders  Company. 

Reprinted  June,  1914-   Revised,  reprinted, 

and  recopyrighted  October,  1916 


Copyright,  1916,  by  W.  B.  Saunders  Company 


Reprinted  January,  1918 


PRINTED    IN    AMERICA 


PRESS    OF 

B.     SAUNDERS     COMPANY 
PHILADELPHIA 


PREFACE  TO  THE  SECOND   EDITION 


THE  very  favorable  reception  everywhere  accorded  to 
this  book  indicates  that  the  work  serves  the  purpose  for 
which  it  was  intended.  In  the  present  edition  the  text 
has  been  revised  to  include  scientific  discoveries  of  the 
past  few  years.  Moreover,  it  has  seemed  wise  to  add  a 
chapter  on  Inflammation  and  one  on  Quarantine,  and  to 
give  a  brief  note  on  the  pathology  of  the  more  important 
infections. 

C.  F.  B. 

M.  G. 
NEW  YORK  CITY. 


402352 


PREFACE 

BACTERIOLOGY  dominates  so  large  a  part  of  the  art  of 
nursing  that  a  correct  understanding  of  the  more  im- 
portant facts  and  principles  of  that  science  is  an  indis- 
pensable part  of  every  nurse's  mental  equipment.  In  the 
following  pages  emphasis  has  been  laid  on  the  immediate 
application  of  the  subject  to  nursing,  and  only  enough 
general  bacteriology  has  been  introduced  to  give  the 
student  a  clear  conception  of  the  principles  underlying 
her  work.  A  perusal  of  the  various  chapters  will  show 
that  a  study  of  all  the  ordinary  modes  of  transmission  of 
infection  has  been  presented.  Sufficient  pathology  has 
been  introduced  to  give  the  student  a  fair  idea  of  the 
nature  of  the  infection  described.  Many  pathogenic 
bacteria  have  been  omitted,  because  their  discussion 
would  have  added  little  or  nothing  to  the  presentation 
of  the  principles  already  laid  down.  While  there  is  no 
gainsaying  the  value  of  individual  laboratory  exercises  in 
the  study  of  bacteriology,  the  writers  feel  that,  so  far  as 
instruction  to  nurses  is  concerned,  simple  practical 
demonstrations  by  the  teacher  may  very  well  be  sub- 
stituted for  individual  laboratory  work.  Suggestions  for 
such  demonstrations  have  been  added  at  the  end  of  the 
chapters. 

NEW  YORK  CITY. 


CONTENTS 


GENERAL   BACTERIOLOGY 

CHAPTER  I  PAGB 

HISTORIC 11 

CHAPTER  II 

CHARACTER  OF  BACTERIA 14 

CHAPTER  III 

METHODS  OF  STUDYING  BACTERIA 22 

CHAPTER  IV 

PREPARATION  OF  STAINED  SMEARS 25 

CHAPTER  V 

CULTIVATION  OF  BACTERIA 27 

CHAPTER  VI 

DISINFECTANTS  AND  ANTISEPTICS 36 

Mercuric  Chlorid 37 

Carbolic  Acid 38 

Crude  Carbolic  Acid 38 

Quicklime 39 

Chlorid  of  Lime 39 

Sulphur  Dioxid 40 

Formaldehyd 40 

lodin 40 

Peroxid  of  Hydrogen 40 

Dakin's  Solution 41 

5 


6 

CHAPTER  VII  PAOE 

STERILIZATION  BY  HEAT 42 

Fire 42 

Dry  Heat 42 

Moist  Heat 43 

Live  Steam 43 

Steam  under  Pressure 45 

CHAPTER  VIII 

RELATION  OF  BACTERIA  TO  DISEASE 47 

Inflammation 49 

CHAPTER  IX 

TRANSMISSION  OF  INFECTIOUS  DISEASES 54 

Terminal  Fumigation 56 

Insects  as  Carriers  of  Infectious  Diseases 56 

CHAPTER  X 

QUARANTINE  IN  THE  CONTROL  OF  INFECTIOUS  DISEASES 59 

CHAPTER  XI 

IMMUNITY 63 

Antitoxins 66 

Bacteriolysins 67 

Agglutinins 69 

Opsonins 72 

Precipitins  and  Other  Antibodies 73 

Anaphylaxis 74 

Serum  and  Vaccine  Therapy 75 


SPECIAL   BACTERIOLOGY 

CHAPTER  XII 
TYPHOID  FEVER 79 

CHAPTER  XIII 
DYSENTERY  AND  CHOLERA 84 

CHAPTER  XIV 
TUBERCULOSIS  .  .  89 


CONTENTS  7 

CHAPTER  XV  PAGE 

DIPHTHERIA 93 

CHAPTER  XVI 

TETANUS f 99 

CHAPTER  XVII 

THE  PNEUMOCOCCUS 102 

CHAPTER  XVIII 
STREPTOCOCCUS  INFECTIONS 105 

CHAPTER  XIX 

STAPHYLOCOCCUS  INFECTIONS 109 

CHAPTER  XX 
THE  MENINGOCOCCUS 112 

CHAPTER  XXI 

THE  GONOCOCCUS 115 

CHAPTER  XXII 
SYPHILIS 117 

CHAPTER  XXIII 

EXANTHEMATA 120 

Scarlet  Fever 120 

Measles  and  German  Measles 121 

Small-pox  and  Cow-pox 122 

CHAPTER  XXIV 

FILTERABLE  VIRUSES 124 

CHAPTER  XXV 

MALARIA • 126 

Yellow  Fever. 128 

Trypanosomiasis 129 


8  CONTENTS 

CHAPTER  XXVI 

PAGE 

BACTERIOLOGY  OF  MILK 130 

CHAPTER  XXVII 

FERMENTED  MILKS 136 

CHAPTER  XXVIII 

BACTERIAL  FOOD  POISONS 139 

CHAPTER  XXIX 

BACTERIOLOGY  OP  WATER 142 

Pollution  to  be  Guarded  Against 142 

Natural  Purification  of  Water 143 

Water-borne  Diseases - 143 

Filtration  of  Water  Supplies 144 

Domestic  Filters 144 

Purification  by  Chlorination 145 

Purification  by  Distillation 146 

Purification  by  Boiling 146 

Bacteriologic  Examination  of  Water 146 

CHAPTER  XXX 

ANIMAL  PARASITES 148 

Tapeworms .-'.., 148 

Trichina 148 

Hookworm 149 

Filaria , . . . : 149 

CHAPTER  XXXI 

PRACTICE  OF  DISINFECTION 150 

Boiling  Water 150 

Steam 150 

Steam  under  Pressure 153 

Dry  Heat 156 

Chemicals 157 

Preparation  of  Patient  for  Operation 158 

To  Prevent  Spread  of  Contagious  Diseases 160 


CONTENTS  9 
CHAPTER  XXXII 

PAGE 

COLLECTION  OF  MATERIAL  FOR  BACTERIOLOGIC  EXAMINATION.  165 

Sputum 165 

Throat  Smears 166 

Water 166 

Milk : 166 

Autopsies ' 166 

Urine 167 

Feces 167 

CHAPTER  XXXIII 

OTHER  IMPORTANT  PATHOGENIC  MICRO-ORGANISMS 168 

Colon  Bacillus 168. 

Pneumobacillus  of  Friedlander 169 

Paratyphoid  Bacilli .  . 169 

Influenza  Bacillus  (Grip  Bacillus) 169 

Whooping-cough  Bacillus 170 

Micrococcus  of  Malta  Fever 170 

Bacillus  Pyocyaneus 171 

Glanders  Bacillus 172 

Bubonic  Plague  Bacillus 173 

Anthrax  Bacillus 174 

Malignant  Edema  Bacillus 175 

Typhus  Fever .  .  175 

Leprosy  Bacillus 176 

Microsporon  Furfur 178 

Oidium  Albicans 179 

Achorion  Schonleinii 179 

Trichophyton  Tonsurans 179 

Poliomyelitis 179 


INDEX..  181 


APPLIED  BACTERIOLOGY  FOR  NURSES 


GENERAL   BACTERIOLOGY 


CHAPTER  I 

HISTORIC 

THE  fact  that  many  diseases  are  caused  by  tiny  liv- 
ing organism  called  bacteria  is  so  universally  accepted 
nowadays  that  it  is  hard  to  realize  our  real  knowledge 
of  bacteria  is  less  than  fifty  years  old.  The  discov- 
ery of  the  relation  between  bacteria  and  disease  has 
revolutionized  medical  practice,  and  has  resulted  in 
the  saving  of  countless  lives  which  formerly  were  lost. 

It  is  true  that,  as  far  back  as  the  seventeenth  century, 
Leeuwenhoek,  of  Delft,  Holland,  had  succeeded  in 
constructing  a  strong  magnifying  glass  by  which  he 
observed  tiny,  living  organisms  in  tartar  scraped  from 
the  teeth,  in  cheese,  rain-water,  decayed  meat,  feces, 
etc.  And,  although  it  was  suggested  that  these  minute 
organisms  were  the  cause  of  a  large  number  of  diseases, 
no  one  succeeded  in  proving  this  relationship.  Finally, 
in  1863,  Davaine,  a  famous  French  physician,  demon- 
strated that  anthrax,  a  disease  common  in  sheep  and 
cattle,  was  caused  by  a  bacterium.  If  we  seek  for  the 

11 


12  APPLIED   BACTERIOLOGY   FOR  NURSES 

reason  why  some  two  hundred  years  elapsed  between 
the  discovery  of  bacteria  by  Leeuwenhoek  and  the 
recognition  of  their  role  in  the  production  of  disease,  we 
find  that  this  was  due  to  the  mechanical  imperfections 
of  the  microscope  and  to  the  difficulties  surrounding 
the  isolation  and  cultivation  of  these  minute  organisms. 
Thanks  to  the  genius  of  Pasteur  and  of  Koch  these 
difficulties  were  successfully  overcome,  and  the  founda- 
tion of  modern  bacteriology  securely  laid.  Prior  to 
this,  however,  Lister,  who  had  carefully  followed 
Pasteur's  work  on  fermentation,  became  convinced  that 
infections  following  surgical  operations  were  due  to  the 
introduction  of  bacteria.  He  accordingly  devised  what 
is  known  as  "antiseptic  surgery,"  whereby  it  was  sought 
to  kill  all  the  germs  which  might  gain  access  to  the  wound 
at  the  time  of  operation  and  at  the  subsequent  dressings, 
and  at  once  caused  an  almost  complete  disappearance 
of  surgical  infections. 

Following  the  splendid  work  of  Pasteur  and  Koch 
progress  in  bacteriology  was  marvelously  rapid.  The 
bacillus  of  typhoid  fever  was  discovered  by  Eberth  in 
1880;  the  bacillus  of  tuberculosis,  by  Koch  in  1882;  the 
spirillum  of  cholera,  by  Koch  in  1884;  the  diphtheria 
bacillus,  by  Klebs  and  Loffler  in  1883;  the  bacillus  of 
lockjaw,  by  Kitasato  in  1889,  and  so  on. 

We  have  already  mentioned  that  following  Leeuwen- 
hoek's  discovery  of  bacteria  these  organisms  were  held 
to  be  the  cause  of  a  great  variety  of  diseases.  In  facti 
for  some  time  people  seemed  "bacteria  mad."  We  now 
know  that  bacteria  are  associated  only  with  a  certain 
group  of  diseases  which  we  call  infectious  diseases.  An 
infectious  disease  is  caused  by  a  living  germ,  though 


HISTORIC  13 

not  necessarily  by  a  bacterium.1  For  example,  typhoid 
fever,  diphtheria,  tuberculosis,  and  pneumonia  are  caused 
by  bacteria;  malaria  and  syphilis,  by  tiny  germs  known 
as  protozoa2 ;  while  certain  diseases  of  the  hair  and  skin 
are  caused  by  fungi.3  The  great  importance  attaching 
to  infectious  diseases  as  a  class  arises  from  the  fact 
that  they  are  communicable.  Moreover,  if  the  germ  of 
a  particular  disease  is  known,  the  possibility  is  given  of 
devising  means  to  prevent  the  spread  of  the  disease,  i.  e., 
the  transmission  of  the  germ  to  others.  For  this  reason 
it  is  important  that  nurses  should  have  some  knowledge 
of  the  nature  and  characteristics  of  germs.  The  study 
of  germs  is  called  bacteriology,  and  this  usually  includes 
not  merely  bacteria,  but  also  protozoa,  yeasts,4  and  fungi. 
The  term  "microbe,"  so  frequently  used  by  the  laity,  is 
synonymous  with  the  term  "germ,"  and  is  usually  taken 
to  include  the  several  classes  of  micro-organisms  just 
mentioned. 

1  BACTERIA  are  microscopic,  unicellular  vegetable  organisms  that 
multiply  by  transverse  division. 

2  PROTOZOA  are  microscopic,  unicellular  animal  organisms. 

3  FUNGI  are  microscopic,  multicellular  vegetable  organisms. 

4  YEASTS   are   microscopic,    unicellular  vegetable   organisms  that 
multiply  by  a  peculiar  process  called  budding. 


CHAPTER  II 

CHARACTER  OF  BACTERIA 

BACTERIA  are  extremely  minute  living  organisms. 
Seen  under  a  powerful  microscope  they  appear  as  little 
rods,  spheres,  or  spirals.  It  is  difficult  for  one  unaccus- 
tomed to  the  use  of  a  microscope  to  conceive  of  the  size 
of  these  micro-organisms.  They  vary  in  size  from  5^ 
to  ^  inch,  so  that  a  tiny  drop  of  pus  often  con- 
tains many  thousand  bacteria.  Even  a  minute  dust 
mote  floating  in  the  air  may  carry  them.  Bacteria  are 
one-celled  organisms,  i.  e.,  each  cell  is  a  complete  in- 
dividual. There  is  no  head,  no  tail,  and  not  even  the 


O 


I         ---  I 


Fig.  1.  —  Comparative  size  of  human  red  blood-corpuscle,  typhoid 
bacillus,  and  influenza  bacillus  (Jordan). 

most  powerful  microscope  reveals  any  special  organs 
within  the  cell.  The  mode  of  life  of  bacteria  is  the 
simplest  that  can  be  conceived.  Placed  in  suitable 
surroundings,  a  bacterium  after  a  time  divides  and 
forms  two  bacteria.  Each  of  these  grows  a  little  until 
of  the  size  of  the  parent,  and  then,  in  turn,  it  also  divides, 
forming  two.  And  so  the  process  goes  on,  each  division 
giving  rise  to  two  bacteria  in  the  place  of  one.  Under 
proper  conditions  certain  bacteria  multiply  very  rapidly, 

14 


CHARACTER  OF    BACTERIA  15 

division  taking  place  about  every  twenty  minutes. 
The  number  of  bacteria  produced  from  a  single  parent 
bacterium  in  twenty-four  hours  thus  becomes  enormous. 
It  is  perfectly  obvious  that  this  rate  of  growth  cannot 
continue  for  very  long,  else  the  entire  world  would 
long  ago  have  become  merely  one  huge  mass  of  bacteria. 
We  shall  study  the  conditions  governing  the  growth  and 
multiplication  of  bacteria  in  a  subsequent  chapter; 
suffice  it  here  to  say  that  further  growth  after  a  time 
ceases,  owing  to  the  accumulation  of  waste-products, 
the  exhaustion  of  the  food  supply,  etc. 

In   form,    bacteria   are    more    or  less   spheric,    rod 
shaped,  or  spiral  shaped.    We  call  the  first  cocci  (singu- 


Fig.  2. — Forms  of  bacteria  (Jordan). 

lar  coccus)]  the  second,  bacilli  (singular  bacillus),  and 
the  third,  spirilla  (singular  spirillum).  The  first  group 
is  still  further  subdivided  according  to  the  manner  in 
which  the  individual  organisms  tend  to  group  them- 
selves when  multiplying.  Thus  a  large  class  of  cocci 
divide  always  in  a  single  plane,  and  so  give  rise  to  a 
string  of  cocci  appearing  like  a  string  of  beads.  Cocci 
growing  in  this  manner  are  termed  streptococci.  In 
another  large  class  the  organisms  divide  in  every  plane, 
so  that  there  is  produced  a  mass  having  somewhat  the 
appearance  of  a  bunch  of  grapes.  Cocci  growing  in  this 
manner  are  termed  staphylococci.  Other  cocci,  on  multi- 


16  APPLIED   BACTERIOLOGY   FOR   NURSES 

plying,  arrange  themselves  in  groups  of  two  each,  and 
these  are  termed  diplococci,  while  still  others  arrange 
themselves  in  groups  of  fours,  and  these  are  termed 
tetrads.  In  medical  bacteriology  besides  bacilli  and 
spirilla,  the  streptococci,  staphylococci,  and  diplococci 
play  an  important  role. 

In  a  preceding  paragraph  it  was  stated  that  bacteria 
multiplied  when  placed  in  proper  surroundings.  On 
the  other  hand,  there  is  considerable  variation  in  the 


Fig.  3. — Bacillus  tetani,  showing  spores.     Pure  culture  on  agar. 
Fuchsin  stain  (Kolle  and  Wassermann). 

behavior  of  different  species  of  bacteria  when  placed  in 
unfavorable  surroundings.  Many  quickly  perish;  others 
live  for  some  time,  and  then  gradually  die  off.  Still 
others  undergo  a  peculiar  transformation  into  a  highly 
resistant  form  known  as  spores.  A  spore  is  a  round  or 
oval  body,  usually  highly  refractive,  and  possessing  a 
high  degree  of  resistance  against  various  destructive 
agents.  Spores,  as  such,  do  not  multiply,  and  may, 
therefore,  be  compared  to  seeds.  A  bacterium  produces 


CHARACTER  OF   BACTERIA 


17 


only  a  single  spore.  Spore  formation  is  limited  to  the 
bacilli.  The  fact  that  spores  are  so  resistant  is  practi- 
cally important,  and  necessitates  a  careful  study  of  the 
principles  underlying  sterilization.  Among  the  spore- 
forming  bacilli  encountered  in  medicine  may  be  men- 
tioned the  bacillus  of  tetanus  (lockjaw),  the  bacillus  of 
anthrax,  and  the  bacillus  of  malignant  edema. 

Some   bacteria   possess   the  power  to   move  about. 
They  are,  therefore,  spoken  of  as  being  motile.    By  em- 


Fig.  4. — Flagella:  Proteus  vulgaris  and  large  spirillum  belonging  to 
the  group  of  sulphur  bacteria  (Zettnow). 


ploying  suitable  methods  the  motile  bacteria  are  seen 
to  have  little  hair-like  appendages,  called  flagella 
(singular  flagettum),  which  act  as  swimming  arms. 
Some  bacteria  have  but  a  single  flagellum,  others  have 
a  little  tuft  at  one  or  both  ends,  while  still  others  have 
flagella  on  all  sides.  The  typhoid  bacillus  is  a  good  ex- 
ample of  a  motile  bacterium;  it  has  flagella  on  all  sides. 
It  is  well  to  remember,  that  not  all  bacteria  produce 
disease.  In  fact,  those  that  do  (the  so-called  patho- 
2 


18  APPLIED   BACTERIOLOGY   FOR   NURSES 

genie  bacteria)  are  only  a  small  proportion  of  the  bac- 
teria thus  far  known.  Many  bacteria  are  very  import- 
ant in  preparing  food  for  plants,  breaking  down  com- 
plex chemic  substances  into  simpler  substances  suitable 
for  plant  absorption.  Still  other  bacteria  are  useful  in 
producing  fermentations,  in  disposing  of  refuse,  liquefy- 
ing sewage,  etc.  Bacteria  are  found  almost  every  where- 
in the  air,  in  water,  in  the  soil,  and  on  everything  we 
touch.  Most  of  the  bacteria  of  the  air,  however,  are 
entirely  harmless,  although  at  one  time  it  was  believed 
that  they  caused  the  infection  of  wounds  during  surgical 
operations.  Lister  used  to  have  a  spray  with  dilute 
carbolic  acid  playing  about  the  operating  room  during 
an  operation  in  order  to  kill  the  bacteria  which  might 
be  in  the  air.  We  have  since  found  out  that  this  is 
unnecessary. 

It  was  stated  above  that  bacteria  multiplied  enor- 
mously when  placed  under  proper  conditions.  These  con- 
ditions relate  mainly  to  food  supply,  to  the  presence  of 
a  suitable  temperature,  sufficient  moisture,  absence  of 
much  light,  presence  or  absence  of  oxygen,  etc.  We 
shall  take  up  the  points  in  the  order  named.  In  suj>- 
plying  living  creatures  with  food,  it  is  always  well 
to  have  the  composition  of  this  as  nearly  as  possible  like 
that  of  their  natural  food.  In  the  case  of  bacteria 
pathogenic  for  man  and  animals  it  is  obvious  that  the 
food  should  have  a  composition  resembling  that  of 
the  animal  body.  This  is  accomplished  by  making  use 
of  broths,  milk,  blood-serum,  and  the  like.  The  same 
principle  applies  to  the  temperature  at  which  the  bac- 
teria are  cultivated.  Just  as  certain  tropical  plants 
require  a  different  temperature  to  grow  than  do  hardy 


CHARACTER   OF  BACTERIA  19 

northern  plants,  so  do  some  bacteria  require  a  warmer 
or  a  colder  environment  than  others.  Bacteria  accus- 
tomed to  grow  in  the  body  of  warm-blooded  animals 
usually  grow  best  at  a  temperature  near  100°  F.  On 
the  other  hand,  the  bacteria  normally  growing  in  water, 
for  example,  usually  grow  best  at  a  temperature  of 
about  60°  F.  Certain  bacteria,  growing  in  manure, 
grow  best  at  a  temperature  considerably  above  100°  F. 


Fig.  5. — Streak  culture  of  the  potato  bacillus  (natural  size), 
showing  an  aerobic  organism  which  will  not  grow  under  a  cover-glass 
(Williams). 

All  bacteria  require  a  certain  amount  of  moisture 
for  their  growth.  Moreover,  many  bacteria  die  if  they 
are  allowed  to  dry. 

The  necessity  for  protecting  bacteria  which  we  wish 
to  cultivate  against  an  undue  amount  of  light,  particu- 
larly against  sunlight,  is  understood  when  one  recalls 


20  APPLIED   BACTERIOLOGY   FOR   NURSES 

that  certain  of  the  light  rays  exert  a  destructive  action 
on  bacteria.  In  fact,  so  resistant  a  germ  as  the  tubercle 
bacillus  may  be  killed  by  several  hours'  exposure  to 
direct  sunlight. 

So  far  as  the -effect  of  oxygen  on  the  growth  of  bac- 
teria is  concerned,  it  is  interesting  to  note  that  there  are 
three  large  classes  of  bacteria,  namely,  those  which 
require  oxygen  for  their  growth,  those  which  will  not 
grow  if  oxygen  is  present,  and  those  which  will  grow 


Fig.  6. — Novy's  jars  for  anaerobic  cultures. 

whether  oxygen  is  present  or  absent.  The  bacteria 
belonging  to  the  first  class  are  called  aerobes,  those 
belonging  to  the  second  class  are  anaerobes,  and  those 
belonging  to  the  third  class  are  calledfacultative  anaerobes. 
The  bacillus  of  diphtheria  is  an  aerobe,  so  is  that  of 
tuberculosis;  the  bacillus  of  tetanus  and  that  of  malig- 
nant edema  are  anaerobes;  the  colon  bacillus  and  the 
bacillus  of  anthrax  are  facultative  anaerobes.  Anaerobic 
cultures  are  conveniently  grown  in  an  atmosphere  of 
hydrogen  in  a  Novy  jar,  or  they  may  be  grown  in  an 


CHARACTER  OF   BACTERIA  21 

atmosphere  of  air  from  which  the  oxygen  has  been  ab- 
stracted by  means  of  chemicals. 

Demonstration. — Moldy  pieces  of  bread.  A  throat  culture  on 
Loffler  serum,  one  or  two  days  old.  Teeth  scrapings,  under  a  cover- 
glass  and  magnified,  unstained.  Hanging-drop  preparation,  prefera- 
bly of  a  motile  organism  (hay  bacillus).  Be  careful  that  the  ob- 
jective of  the  microscope  is  not  pushed  through  the  cover-glass. 
Spores  (an  old  culture  of  hay  bacilli). 


CHAPTER  III 
METHODS  OF  STUDYING  BACTERIA 

WHILE  bacteria  can  be  seen  with  high-power  magnify- 
ing glasses,  it  is  impossible  to  study  their  form  without 
a  compound  microscope.  Such  an  instrument  is  shown 
in  Fig.  7. 

It  consists  of  a  heavy  foot  or  base  bearing  an  upright 
post,  to  which  the  stage  and  the  tube  are  attached. 
The  object  to  be  examined  is  placed  on  the  stage,  and 
light  is  thrown  up  from  the  mirror  beneath,  through  the 
object,  and  into  the  series  of  lenses  in  the  tube.  The 
tube  is  moved  up  and  down  by  means  of  two  screws,  one 
called  the  coarse  adjustment,  the  other  called  the  fine 
adjustment.  Fitting  into  the  upper  end  of  the  tube  are 
various  eye-pieces  or  oculars.  These  are  of  varying 
power  and  are  usually  numbered  from  1  to  5.  Attached 
to  the  lower  end  of  the  tube  is  a  so-called  nose-piece, 
carrying  two  or  three  "objectives/'  each  objective  con- 
sisting of  a  series  of  lenses  mounted  together.  The 
objectives  are  usually  distinguished  by  numbers  (3,  5, 
and  7)  or  by  fractions  (§,  J,  and  J  inch).  When 
using  the  higher  powers'of  the  microscope  it  is  important 
to  have  strong  illumination  from  the  mirror.  In  order 
to  bring  this  about  a  series  of  lenses,  called  the  con- 
denser, is  placed  between  the  mirror  and  the  stage. 
But  even  with  this  equipment  it  is  difficult  to  study 
the  finer  details  of  bacterial  structure.  This  can  only 


METHODS  OF   STUDYING   BACTERIA 


23 


be  satisfactorily  accomplished  by  staining  the  bacteria 
and  examining  them  by  means  of  very  high-power  ob- 
jectives, which  dip  into  a  drop  of  cedar  oil  placed 
directly  on  the  specimen  to  be  examined.  Such  objec- 
tives are  spoken  of  as  oil-immersion  objectives;  the  one 


Ocular 


Graduated 
Draw-tube 


Charge  Adjuster 


Fine  Adjuster 


Objectives  and 
Nose-piece 


Substage  with 
Diaphragm 
and  Condenser 


Fig.  7. — Bacteriologic  microscope  (Ball). 

in  common  use,  the  ^  inch,  when  used  with  a  No.  5 
eye-piece,  magnifies  about  1200  times.  For  the  staining 
of  bacteria  we  usually  employ  some  of  the  coal-tar  dyes; 
such  as  methylene-blue,  fuchsin,  gentian- violet,  etc. 
The  appearance  of  such  stained  bacteria  is  well  shown 
in  Plate  1.  The  use  of  these  stains  has  a  further 


24  APPLIED   BACTERIOLOGY   FOR  NURSES 

value,  in  that  it  often  helps  to  differentiate  bacteria 
from  one  another.  This  will  be  seen  when  we  study 
Gram's  stain  and  the  stain  for  tubercle  bacilli  (p.  26). 

Demonstration. — Show  a  reading  glass,  and  a  high-power  magni- 
fying glass  such  as  is  used  to  count  threads  in  a  woven  fabric. 
(Image  erect.) 

Demonstrate  the  compound  microscope.     (Image  inverted.) 


CHAPTER  IV 
PREPARATION  OF  STAINED  SMEARS 

IN  preparing  bacteria  for  microscopic  examination  a 
tiny  bit  of  the  material  (pus;  sputum,  exudate,  culture, 
etc.)  is  thinly  spread  on  a  glass  slide  and  allowed  to  dry. 
Then  the  slide  is  passed  several  times  through  the  flame 
in  order  to  "fix"  the  preparation.  By  this  is  meant  the 
drying,  killing,  and  coagulating  of  the  material,  so  that 
it  will  remain  fixed  to  the  slide  and  not  wash  off  in  the 
staining  fluid.  For  the  ordinary  examination  the 
preparation  is  next  flooded  with  the  staining  fluid — e.  g., 
watery  solution  of  methylene-blue — and  allowed  to 
stain  for  several  minutes.  The  stain  is  poured  off,  the 
slide  washed  in  water,  dried  with  blotting-paper  and  in 
air,  and  is  then  ready  to  be  examined.  The  simple 
stains  in  common  use  are  watery  solutions  of  methylene- 
blue,  of  gentian- violet,  or  of  fuchsin.  Some  bacteria, 
however,  do  not  take  these  simple  stains  readily,  and 
it  is  necessary  to  add  something  to  the  staining  fluid  to 
cause  the  stain  to  "bite  in."  The  substance  thus  added 
is  called  a  mordant.  Carbolic  acid  is  an  excellent 
mordant,  a  solution  of  carbolic  acid  and  fuchsin  being 
extensively  used  to  stain  tubercle  bacilli. 

It  was  said  above  that  stains  were  also  used  in  identi- 
fying bacteria.  Most  bacteria,  for  example,  when  stained 
and  then  treated  with  acids  quickly  lose  their  color. 
Some,  however,  withstand  the  action  of  acids,  retain- 

25 


26  APPLIED   BACTERIOLOGY  FOR   NURSES 

ing  their  color  even  after  prolonged  contact.  These 
are  spoken  of  as  ' 'acid-fast"  bacteria.  This  test  is  ex- 
tensively used  in  identifying  tubercle  bacilli,  for  these 
belong  to  the  acid-fast  group.  (See  Plate  1.) 

Another  staining  method  largely  used  in  identifying 
bacteria  is  one  devised  by  Gram.  This  is  carried  out 
as  follows:  The  bacteria,  spread  and  fixed  on  the  slide 
in  the  usual  way,  are  stained  with  a  solution  of  gentian- 
violet  with  the  aid  of  a  little  heat.  At  the  end  of 
several  minutes  the  stain  is  poured  off,  and,  without 
washing,  the  slide  treated  with  a  solution  of  iodin. 
Following  this,  the  preparation  is  washed  with  absolute 
alcohol  and  then  with  water.  When  treated  in  this 
way  certain  bacteria  are  found  to  retain  the  original 
violet  stain,  while  others  lose  it  during  the  alcohol  treat- 
ment. This  is  a  very  valuable  reaction,  and  is  exten- 
sively used  in  identifying  the  germs  of  meningitis, 
gonorrhea,  etc.  Bacteria  which  retain  the  violet  stain 
when  treated  according  to  Gram's  method  are  called 
"Gram-positive/'  while  those  which  lose  their  stain  are 
called  "Gram-negative." 

In  passing  we  may  say  that,  in  addition  to  these 
ordinary  staining  methods,  special  procedures  have  been 
devised  for  the  demonstration  of  flagella  in  motile  bac- 
teria and  for  staining  spores,  capsules,  etc. 

The  teacher  is  to  demonstrate  simple  staining,  explaining  the 
various  steps,  tubercle  staining  (Ziehl's  method),  and  Gram's  stain. 

For  this  exercise  let  the  students  examine  as  many  Stained 
specimens  as  possible,  to  fix  in  their  minds  the  appearance  and 
relative  size  of  bacteria. 


CHAPTER  V 
CULTIVATION  OF  BACTERIA 

IN  order  to  properly  study  bacteria  it  is  absolutely 
essential  that  they  be  grown  by  themselves,  i.  e.}  not 


JT, 


a  b  c 

Fig.  8. — Media  in  tubes:  a,  Broth;  6,  agar  slant;  c,  potato  (Hiss  and 

Zinsser). 

mixed  with  a  lot  of  other  bacteria.    In  other  words,  it 
is  necessary  to  obtain  a  pure  culture.    We  shall  assume 

27 


28  APPLIED    BACTERIOLOGY    FOR   NURSES 

that  we  have  such  a  culture;  let  us  now  consider  the 
methods  by  which  we  continue  to  grow  the  same. 
Our  first  step  is  to  plant  the  bacteria  either  in  a  fluid 
culture-medium,  such  as  beef -broth,  milk,  etc.,  or  on  the 


Fig.  9. — Platinum  wires  for  bacteriologic  use. 

surface  of  a  solid  medium,  such  as  gelatin,  agar,  solidi- 
fied blood-serum,  potato,  etc.  It  is  obvious  that  these 
culture-media  must  be  absolutely  free  from  other  germs, 
i.  e.,  they  must  be  perfectly  sterile.  In  planting  the 


Fig.  10. — Method  of  holding  tubes  during  inoculation  (McFarland). 

culture,  we  have  at  hand  the  tube  containing  our  original 
pure  culture  and  a  tube  of  the  sterile  medium,  e.  g., 
sterile  broth,  closed  at  the  top  with  a  cotton  plug.  All 
we  need  to  do  is  to  transfer  a  little  loopful  of  culture  by 


CULTIVATION   OF   BACTERIA 


29 


means  of  the  platinum  wire  loop  to  the  tube  of  sterile 
broth.  In  order  to  avoid  carrying  along  other  germs, 
however,  we  first  hold  the  wire  loop  in  the  flame  until 
it  glows,  thus  destroying  any  germs  that  may  have 


Fig.  11. — Incubator  (Eyre). 

lodged  on  the  wire.  The  loop  cools  in  a  moment,  the 
culture  is  transferred,  the  tubes  are  again  closed  with 
the  cotton  plugs,  and  the  wire  is  at  once  passed  through 
the  flame  before  being  laid  down.  Thus  all  danger  of 
spreading  the  germs  about  is  avoided. 


30  APPLIED   BACTERIOLOGY   FOR   NURSES 

The  freshly  planted   culture  is  now  placed  in  the 
incubator.     This  is  a  kind  of  oven  whose  walls  are  filled 


Fig.   12. — Streptococcus  pyogenes,  culture  on  agar.     Slightly  en- 
larged (Williams). 

with  water,  and  whose  interior  is  kept  at  a  uniform  tem- 
perature by  means  of  a  lamp  or  gas  flame  controlled  by 


CULTIVATION   OF   BACTERIA 


31 


a  suitable  heat  regulator.  For  the  ordinary  pathogenic 
bacteria  the  incubator  is  set  to  maintain  a  constant  tem- 
perature of  about  99°  F. 

In  studying  the  bacteria  of  water,  a  temperature  of 
60°  F.  is  usually  employed.  The  general  type  of  incu- 
bator is  shown  in  Fig.  11,  page  29. 


Fig.  13.— Streak  plate.    (From  Hiss  and  Zinsser,     A  Text-Book  of 
Bacteriology,"  D.  Appleton  &  Co.,  publishers.) 

After  remaining  in  the  incubator  for  twelve  to  twenty 
hours  it  will  be  noticed  that  the  appearance  of  the  beef- 
broth  has  changed.  Originally  perfectly  clear,  it  now 
is  more  or  less  uniformly  cloudy,  or  it  may  have  a 
cloudy  sediment  or  be  covered  with  a  scum.  If  the  cul- 


32  APPLIED   BACTERIOLOGY   FOR   NURSES 

ture  was  planted  on  sterile  agar  (a  kind  of  gelatin)  it 
will  now  be  found  to  be  covered  with  a  peculiar,  more  or 
less  slimy  mass,  or  with  a  number  of  small,  rounded  spots, 
This  cloudiness  in  the  fluid  culture,  or  this  slimy  mass 
on  the  solid  cultures,  is  the  new  growth,  and  is  made 
up  of  millions  of  tiny  bacteria.  Just  as  in  planting  seed 
in  the  ground,  a  plant  arises  from  each  seed;  so,  in  plant- 
ing bacteria  on  the  surface  of  a  solid  medium,  wherever 
a  single  bacterium  was  deposited  a  whole  group  of 
similar  bacteria  develop.  These  groups  become  visible 
to  the  naked  eye,  forming  usually  more  or  less  rounded 


Fig.  14. — Petri  dish  for  making  plate  cultures  (McFarland). 

masses,  varying  in  size  from  that  of  a  pin's  head  to 
disks  J  inch  in  diameter.  Such  masses  of  similar  bac- 
teria, the  offspring  of  a  single  individual,  are  spoken 
of  as  "colonies."  The  number  of  colonies  developing 
is  thus  an  index  of  the  number  of  living  germs  in  the 
material  planted.  If  the  bacteria  originally  planted 
were  very  numerous,  the  colonies  developing  are  so 
closely  crowded  that  they  form  one  continuous  film, 
in  which  it  is  impossible  to  distinguish  separate  colonies. 
It  is  apparent  that  we  can  discover  the  number  of  living 
germs  in  a  specimen  of  fluid  by  planting  a  known 
quantity  of  the  fluid  on  a  solid  medium,  growing  the 
culture,  and  then  noting  the  number  of  colonies  which 
develop.  This  is  facilitated  by  using  shallow  flat  glass 


CULTIVATION   OF   BACTERIA  33 

dishes,  called  "Petri  dishes"  or  "plates."  This  "plat- 
ing" method  is  extensively  used  to  determine  the 
number  of  living  bacteria  in  milk  and  in  water. 


Fig.  15.- — Pouring  plates  (Eyre). 

Plate  cultures  are  also  employed  in  isolating  bacteria 
in  pure  cultures.     Without  entering  into  the  details  of 


Fig.  16. — Appearance  of  colonies  on  gelatin  in  Petri  dish  (Williams). 

the  method,  we  may  say  that  in  general  it  consists  in 
the  preparation  of  a  number  of  plate  cultures  from  the 
material  to  be  examined,  selecting  the  plate  on  which 

3 


34  APPLIED   BACTERIOLOGY   FOR   NURSES 

the  colonies  are  not  too  closely  crowded,  and  then,  by 
means  of  a  sterile  straight  platinum  wire,  carefully 
transferring  some  of  the  bacteria  from  a  single  colony  to 
a  tube  of  sterile  medium.  This  process  is  spoken  of  as 
"fishing"  a  plate.  It  is  obvious  that,  even  though  the 
original  material  contained  many  different  kinds  of 
bacteriaj  the  cultures  obtained  by  "fishing"  will  each 
contain  but  a  single  kind  in  pure  culture. 


Fig.  17. — Smith's  fermentation-tube  (McFarland). 

The  cultivation  of  bacteria  on  different  media  con- 
stitutes an  important  means  of  studying  and  identify- 
ing the  various  species.  For  example,  certain  bacteria 
when  grown  in  gelatin  cause  the  gelatin  to  become 
fluid,  while  others  do  not.  Certain  bacteria  cause  milk 
to  turn  sour  and  coagulate,  some  cause  it  to  become 
putrid,  while  others  apparently  leave  it  unchanged. 


CULTIVATION   OF   BACTERIA  35 

In  media-containing  sugars  some  bacteria  ferment  the 
sugars  with  the  production  of  acid,  others  with  the 
production  of  gas  and  acid,  while  still  others  do  not  fer- 
ment the  sugar  at  all.  In  studying  the  production  of 
acid  we  can  add  a  little  litmus  to  the  medium  and  note 
whether  the  blue  color  changes  to  red.  The  formation 
of  gas  is  best  observed  by  growing  the  culture  in  a  fer- 
mentation-tube. 

Demonstration. — The  teacher  should  inoculate  various  media, 
both  liquid  and  solid,  using  organisms  growing  both  at  room  tem- 
perature and  body  heat  (e.  g.%  hay  bacillus),  and  organisms  growing 
only  at  body  heat  (e.  g.,  pneumococcus) .  Some  of  the  latter  variety 
should  be  inoculated  in  duplicate,  and  the  duplicate  kept  at  room 
temperature,  to  show  that  there  will  be  no  growth  under  these 
conditions.  Agar-plate  cultures  should  be  made  from  milk  (diluted) 
and  from  tap- water. 

Streak-plate  cultures  may  be  made  from  the  throat  or  from  teeth 
scrapings. 


CHAPTER  VI 
RELATION  OF  BACTERIA  TO  DESTRUCTIVE  INFLUENCES 

DISINFECTANTS  AND  ANTISEPTICS 

IN  a  previous  chapter  it  was  pointed  out  that  bacteria 
required  a  certain  degree  of  heat  in  order  to  thrive. 
For  most  pathogenic  bacteria  this  is  about  100°  F. 
Higher  temperatures,  on  the  other  hand,  exert  an  in- 
jurious action  on  bacteria,  so  that  even  a  short  ex- 
posure to  the  temperature  of  boiling  water  quickly 
kills  most  pathogenic  bacteria.  Destruction  of  bacteria 
can  also  be  effected  by  prolonged  exposure  to  tempera- 
tures considerably  less  than  the  boiling-point  of  water. 
This  is  spoken  of  as  "pasteurization,"  after  Pasteur, 
who  first  applied  this  method  of  killing  bacteria.  The 
effect  of  low  temperatures  on  bacteria  varies  consider- 
ably with  different  species.  Bacteria  accustomed  to 
grow  at  body  temperature  usually  cease  to  grow  or 
grow  very  slowly  at  ordinary  room  temperatures. 
There  is  practically  no  growth  at  all  at  40°  F.  At 
freezing  temperature  many  bacteria  die  off,  but  even 
the  low  temperature  of  liquid  air  does  not  certainly 
kill  all  forms. 

Bacteria  also  vary  in  their  resistance  to  drying,  the 
vegetative  forms  usually  drying  quickly,  while  certain 
spore  forms  appear  to  resist  drying  indefinitely.  As 
has  already  been  pointed  out,  direct  sunlight  exerts  a 


37 

destructive  action  on  bacteria.  The  combination  of 
heat,  drying,  and  sunlight  is  extremely  efficacious  in 
killing  bacteria. 

The  study  of  chemicals  which  exert  a  destructive  in- 
fluence on  bacteria  (disinfectants)  is  of  great  practical 
importance.  Depending  on  the  intensity  of  their  ac- 
tion, we  usually  speak  of  these  substances  as  being 
either  "germicides"  (germ  killers)  or  "antiseptics" 
(preventing  germ  growth).  Every  germicide  in  diluted 
form  is  an  antiseptic.  The  conditions  under  which  the 
disinfectant  acts  is  of  the  greatest  practical  importance. 
Thus,  carbolic  acid  acts  better  in  5  per  cent,  solution 
than  in  higher  concentrations,  and  the  efficiency  is 
increased  by  the  addition  of  salt,  but  diminished  by  the 
presence  of  alcohol.  The  rate  of  penetration  into  bac- 
terial cells  decreases  as  the  concentration  increases 
above  a  certain  limit.  The  temperature  at  which  the 
process  is  carried  on  also  has  a  marked  influence  on  the 
rate  of  disinfection.  The  presence  of  albuminous 
substances  largely  interferes  with  the  action  of  certain 
disinfectants,  notably  with  mercury  bichlorid.  The 
following  are  some  of  the  more  commonly  used  disin- 
fectants: 

Mercuric  chlorid,  also  called  corrosive  sublimate, 
bichlorid  of  mercury,  or,  for  short,  "bichlorid,"  while 
strongly  germicidal,  has  the  disadvantage  of  being 
extremely  poisonous,  of  forming  insoluble  and  inert 
compounds  with  albuminous  substances,  and  of  acting 
on  metals.  Despite  these  drawbacks,  however,  this  is 
one  of  the  most  commonly  used  disinfectants  at  the 
present  day.  It  is  employed  largely  in  the  form  of  ready 
made  tablets,  containing  usually  sufficient  "bichlorid"  to 


38  APPLIED   BACTERIOLOGY   FOR  NURSES 

make  a  solution  1 : 1000  when  one  tablet  is  dissolved  in 
a  pint  of  water.  Most  of  the  tablets  contain  either 
citric  or  tartaric  acid  or  ammonium  chlorid  to  prevent 
the  formation  of  insoluble  compounds  with  albuminous 
matter.  Many  of  the  tablets  also  contain  some  harmless 
blue,  pink,  or  yellow  coloring-matter  to  aid  in  identify- 
ing the  solution.  For  ordinary  use  solutions  of  1 : 1000 
will  suffice,  when  brought  into  contact  with  bacteria, 
to  kill  the  vegetative  forms  within  fifteen  minutes. 
Stronger  solutions,  however,  must  be  employed  when 
much  organic  matter  is  present.  Mercuric  chlorid 
should  not  be  employed  to  disinfect  metal  instruments, 
as  it  quickly  ruins  them  by  its  action. 

Carbolic  acid,  or  phenol,  is  a  white  crystalline  sub- 
stance readily  liquefied  by  heat.  It  can  be  kept  liquid 
by  the  addition  of  5  per  cent,  water  or  glycerin,  making 
what  is  sold  in  the  drug  stores  as  "pure  carbolic  acid.7' 
For  disinfecting  purposes  it  is  ordinarily  used  in  the 
form  of  a  5  per  cent,  solution  in  water,  and,  while  it  is 
less  powerful  than  mercuric  chlorid,  it  has  the  advantage 
of  being  only  slightly  affected  by  albuminous  material, 
and  of  not  acting  on  metals.  Its  efficiency  is  increased 
by  the  addition  of  common  salt  up  to  saturation:  1:400 
kills  the  less  resistant  bacteria,  and  1:100  kills  the 
remainder.  .A  5  per  cent,  solution  kills  the  less  resistant 
spores  within  a  few  hours,  and  the  more  resistant  in 
from  a  day  to  four  weeks. 

Crude  carbolic  acid  consists  mainly  of  cresols  and 
very  little  phenol.  By  saponification  of  mixtures  of 
cresols  and  neutral  tar  oils  a  product  is  obtained  which 
makes  an  emulsion  with  water.  Creolin  is  a  type  of 
numerous  preparations  of  this  character.  They  are  al) 


BACTERIA,    DESTRUCTIVE   INFLUENCES  39 

poisonous  and  sensitive  to  albuminoids.  Moreover, 
these  emulsions  have  the  disadvantage  of  being  opaque. 
Lysol  is  mainly  a  solution  of  the  cresols  in  fat  or  linseed 
oil  saponified  with  addition  of  alkali.  It  gives  a  clear 
solution  with  water,  having  marked  germicidal  powers 
and  considerable  solvency  for  grease.  It  is  extensively 
used  in  the  form  of  a  1  per  cent,  solution  in  gynecologic 
and  obstetric  practice.  Tricresol,  a  refined  mixture  of  the 
three  cresols,  is  soluble  in  water  to  the  extent  of  2.5  per 
cent.  It  is  about  three  times  the  strength  of  carbolic 
acid. 

Quicklime,  used  in  the  form  of  freshly  slaked  lime 
suspended  in  water,  is  a  powerful  disinfectant.  A  1  per 
cent,  watery  solution  of  the  freshly  slaked  lime  kills 
bacteria  which  are  not  in  the  spore  form  within  a  few 
hours.  A  3  per  cent,  solution  kills  typhoid  bacilli  in  one 
hour,  while  a  20  per  cent,  solution,  added  to  equal  parts 
of  feces  or  other  filth  and  thoroughly  mixed,  will  com- 
pletely sterilize  them  within  one  hour. 

Chlorid  of  lime,  so  called  (really  chlorinated  lime), 
depends  for  its  efficacy  on  the  chlorin  it  contains,  and, 
as  this  is  readily  lost  on  exposure  to  the  air,  it  is  im- 
portant that  chlorid  of  lime  be  kept  in  tight  containers. 
A  solution  in  water  containing  0.5  to  1  per  cent,  of 
chlorid  of  lime  will  kill  most  bacteria  in  one  to  five 
minutes.  A  5  per  cent,  solution  usually  destroys  spores 
within  one  hour.  Chlorid  of  lime  is  particularly  useful 
in  the  disinfection  of  stools.  Together  with  washing-soda 
it  is  also  extensively  used  as  a  hand  disinfectant  by 
surgeons. 

In  recent  years  chlorinated  lime  is  used  extensively 
in  disinfecting  municipal  water-supplies.  When  so  used 


40  APPLIED    BACTERIOLOGY  FOR   NURSES 

about  15  pounds  are  added  to  1,000,000  gallons  of  water. 
This  is  equivalent  to  approximately  0.5  part  free  chlorin 
per  1,000,000  parts  of  water.  (See  also  page  145.) 

Sulphur  dioxid  gas,  produced  by  burning  sulphur  in 
air,  was  formerly  extensively  used  as  a  disinfectant  for 
sick  rooms,  but  has  now  been  largely  discarded  in  favor 
of  formaldehyd.  Ordinarily  4  pounds  of  sulphur  are 
burned  for  each  1000  cubic  feet  of  air  space,  and  the 
room  is  kept  sealed  for  at  least  eight  hours.  In  order  to 
be  efficacious  the  air  in  the  room  in  which  the  sulphur 
is  burned  should  be  moist.  Sulphur  fumigation  is  still 
largely  used  to  kill  rats  and  vermin  in  combating  the 
spread  of  plague. 

Formaldehyd  is  a  gaseous  compound  having  an  ex- 
tremely irritating  odor.  It  is  most  conveniently  used 
in  the  form  of  a  watery  solution  containing  about  40 
per  cent,  of  the  gas,  and  known  commercially  as  "for- 
malin." A  2  per  cent,  watery  solution  of  formalin 
destroys  the  vegetative  forms  of  bacteria  within  five 
minutes.  In  the  form  of  the  gas  formaldehyd  is  ex- 
tensively used  in  the  disinfection  of  sick  rooms.  At 
least  4  ounces  of  formaldehyd  should  be  allowed  for 
each  1000  cubic  feet  of  air  space.  The  details  of  such 
disinfection  are  discussed  on  p.  163. 

lodin,  in  the  form  of  tincture  of  iodin,  is  extensively 
used  as  a  disinfectant  of  the  skin  for  surgical  operations. 

Peroxid  of  hydrogen  (H202)  is  an  energetic  disin- 
fectant. A  20  per  cent,  solution  (a  good  commercial 
hydrogen  peroxid)  will  quickly  destroy  the  pus-produc- 
ing cocci  and  spore-free  bacteria.  It  combines  with 
organic  matter,  becoming  inert.  It  is  prompt  in  its 
action  and  not  poisonous,  but  apt  to  deteriorate  if  not 


BACTEKIA,  DESTRUCTIVE  INFLUENCES 


41 


properly  kept.  It  is  extensively  used  to  wash  out 
abscess-cavities  and  purulent  sinuses,  and  also  as  a 
gargle  and  mouth-wash. 

Demonstration. — The  teacher  should  inoculate  a  loopful  from  a 
twenty-four-hour  broth  culture  of  typhoid  (or  colon)  bacilli  into  the 
following  tubes:  and  make  subcultures  from  each  of  these  tubes  at 


10  c.c. 


Carbolic 


— 

^-~-^-=-^~- 

_.  _- 

^'i1-:-^ 

loc.e. 

1-1000 

Bichlorld 

^-ET-ET? 

IOC.C. 

plain. 
Sterile 
Water 

Fig.  18. 

the  end  of  one  minute  or  five  minutes  by  inoculating  a  loopful  from 
these  tubes  into  plain  sterile  broth. 

Instead  of  making  broth  subcultures,  agar  poured  plate  cultures 
can  be  made. 

Dakin's  Solution.1 — Experience  having  shown  that  there 
were  certain  drawbacks  to  Dakin's  original  formula,  the 
following  method  of  preparing  the  Dakin  hypochlorite 
solution  used  by  Carrel  was  devised  by  Daufresne. 

To  prepare  10  litres  of  solution  weigh  out  exactly: 
Chloride  of  lime  (having  2§  per  cent,  active  chlorine) ....  184  grams. 
Carbonate  of  soda,  anhydrous  (or  carbonate  of  soda, 

crystals,  262  grams) 92  grams. 

Bicarbonate  of  soda 76  grams. 

Into  a  12-litre  flask  place  the  chloride  of  lime  and  5 

1  This  is  taken,  by  permission,  from  "The  Treatment  of  Infected 
Wounds,"  by  A.  Carrel  and  G.  Dehelly.  New  York,  Paul  B  Hoeber, 
1917. 


41  A  DARIN'S  SOLUTION 

litres  of  tap-water;  shake  vigorously  two  or  three  times  and 
leave  it  all  night. 

Dissolve  the  carbonate  and  bicarbonate  of  soda  in  5 
litres  of  cold  water. 

Pour  the  solution  of  soda  salts  into  the  flask  containing 
the  suspended  chloride  of  lime,  shake  well  during  one  min- 
ute, and  set  aside  to  allow  the  lime  carbonate  to  settle. 

At  the  end  of  half  an  hour  siphon  off  the  clear  liquid  and 
filter  it  through  a  double  paper  to  make  it  perfectly  clear. 

The  antiseptic  solution  is  then  ready  for-  surgical  use. 
It  should  contain  0.475  per  cent,  of  hypochlorite  of  soda, 
with  small  quantities  of  neutral  salts  of  soda.  It  is  iso- 
tonic  to  blood  serum. 

Keep  the  solution  in  a  cool  place,  away  from  light. 

If  the  chloride  of  lime  used  contains  materially  more  or 
less  active  chlorine  than  25  per  cent.,  it  is  important  to 
alter  the  proportion  of  the  three  substances  used  in  the 
preparation  of  the  solution.  For  this  reason  the  amount  of 
active  chlorine  in  the  sample  should  be  tested  as  follows : 

Weigh  out  an  average  sample  of  20  grams,  stir  it  up  in  a 
litre  of  water  as  perfectly  as  possible,  and  allow  it  to  stand 
some  hours.  Measure  off  10  c.c.  of  the  clear  liquid,  add  to 
it  20  c.c.  of  a  10  per  cent,  solution  of  iodide,  2  c.c.  of  acetic 
acid  or  hydrochloric  acid,  then  to  the  mixture  add  drop  by 
drop  a  decinormal  solution  of  hyposulphite  of  soda  (2.48 
per  cent.),  up  to  decolorization.  The  number  (n)  of  cubic 
centimeters  of  hyposulphite  employed  multiplied  by  1775 
will  give  the  weight  (N)  of  active  chlorine  contained  in  100 
grams  of  the  chloride  of  lime. 

This  estimation  must  be  carried  out  for  each  consign- 
ment received.  Should  the  result  obtained  differ  from  the 


BACTERIA,    DESTRUCTIVE    INFLUENCES  41 B 

average  figure  of  20  per  cent.,  the  proportion  of  the  three 
substances  used  in  the  preparation  of  the  solution  must  be 
reduced  or  augmented.  This  is  readily  found  by  multi- 
plying each  of  the  three  sets  of  figures,  184, 192,  and  76,  by 
the  factor  ^  in  which  N  represents  the  actual  chlorine  per 
cent,  in  the  chloride  of  lime. 

The  following  table  drawn  up  by  Daufresne  is  intended 
to  avoid  this  calculation  and  to  give  directly,  according  to 
the  amount  of  active  chlorine  contained  in  the  chloride  of 
lime,  the  amounts  needed  to  obtain  a  correct  solution. 

Quantities  to  be  Used  to  Obtain  10  Litres  of  Solution  of 

Hypochlorite  of  0.475  Per  Cent. 
Titration  of  Chloride 
of  Lime  (Cl  per  cent.) 
(English  degrees). 

20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 

It  is  well  to  titrate  the  finished  product  to  measure  the 
content  of  hypochlorite  of  soda.  This  is  done  as  follows : 

Measure  off  10  c.c.  of  the  solution,  add  20  c.c.  of  10  per 
cent,  solution  of  iodide  of  potassium,  2  c.c.  of  acetic  acid, 
then  drop  by  drop  a  decinormal  solution  of  hyposulphite 
up  to  decolorization.  The  number  of  cubic  centimeters 
used  multiplied  by  0.03725  will  give  the  weight  of  hypo- 
chlorite of  soda  contained  in  100  c.c.  of  solution. 


Chloride  of 

Carbonate  of 

Bicarbonate  of 

lime. 
Grams. 

Soda,   anhydrous. 
Grams. 

soda. 
Grams. 

230 

115 

96 

220 

110 

92 

210 

105 

88 

200 

100 

84 

192 

96 

80 

184 

92 

76 

177 

89 

72 

170 

85 

70 

164 

82 

68 

159 

80 

66 

154 

77 

64 

148 

74 

62 

144 

72 

60 

140 

70. 

59 

135 

68 

57 

132 

66 

55 

128 

64 

53 

124 

62 

52 

CHAPTER  VII 
STERILIZATION  BY  HEAT 

IN  making  use  of  heat  to  destroy  bacteria  the  method 
employed  depends  largely  on  the  character  of  the  mate- 
rial to  be  sterilized.  Heat  may  be  used  in  the  form  of 
fire,  i.  e.j  the  naked  flame,  or  as  dry  heat,  or  as  boiling 
water,  or  live  steam,  or  live  steam  under  pressure. 

(1)  Fire. — Many  infected  articles  which  it  is  desired 
to  be  rid  of  can  be  burned  in  the  fire,  thus  absolutely 
destroying  the  infectious  bacteria.    Infected  mattresses, 
rugs,  books,  papers,  and  magazines,  toys,  pus-soaked 
dressings,    paper   sputum    cups    and    paper   handker- 
chiefs, and  other  similar  articles  are  often  best  disposed 
of  in  this  way.    In  an  emergency  it  is  sometimes  very 
convenient  to  sterilize  a  knife  or  other  surgical  instru- 
ment by  passing  it  through  the  flame,  or  by  dipping  it 
into  alcohol  and  then  lighting  the  alcohol. 

(2)  Dry  Heat. — In  many  instances  the  use  of  fire  is 
out  of  the  question.    In  such  cases  we  may  often  employ 
dry  heat  to  advantage.     In  bacteriologic  laboratories 
special  ovens  are  constructed  for  sterilizing  glassware, 
etc.,  by  means  of  dry  heat.    In  the  home  the  oven  of  the 
kitchen  stove  will  usually  answer  equally  well.     The 
temperature  of  the  oven  should  range  about  300°  F., 
and  the  articles  should  remain  exposed  for  about  an 
hour. 

42 


STERILIZATION  BY  HEAT  43 

(3)  Moist  Heat— It  has  been  found  that  the  presence 
of  moisture  markedly  increases  the  destructive  effect 
of  heat.  The  simplest  method  of  combining  these  two 
factors  is  to  boil  the  articles  to  be  sterilized  in  water. 
Surgical  instruments  are  usually  sterilized  in  this  way, 


Fig.  19. — Hot-air  sterilizer  (McFarland). 

and  so  are  catheters,  douche-nozzles,  hypodermic  nee- 
dles, etc. 

(4)  Live  Steam. — Another  method  of  using  moist 
heat  is  by  means  of  live  steam  in  a  steam  sterilizer. 
The  accompanying  figure  shows  the  construction  of  the 


44  APPLIED   BACTERIOLOGY   FOR   NURSES 

Arnold  steam  sterilizer.  This  consists  of  a  very  shallow 
boiling  pan,  a  steam  chamber,  which  is  surrounded  by 
the  removable  hood,  and  a  large  pan,  which  catches  the 
drip  water.  The  large  pan  is  connected  with  the  small 
pan  by  a  number  of  small  openings,  thus  constantly 
keeping  a  supply  of  water  in  the  boiling  pan.  The  ad- 
vantage of  this  design  is  the  rapidity  with  which  steam 


Fig.  20. — Arnold  steam  sterilizer  (Fowler). 

is  developed  and  the  little  attention  the  apparatus 
requires  when  in  operation.  The  temperature  within 
the  steam  chamber  is  approximately  that  of  boiling 
water,  212°  F.  This  form  of  sterilizer  is  extensively 
used  to  sterilize  the  various  nutrient  media  used  for 
growing  bacteria.  In  order  to  be  certain  that  steriliza- 
tion has  been  complete  it  is  customary  to  sterilize  these 


STERILIZATION   BY  HEAT  45 

in  the  Arnold  sterilizer  for  an  hour  on  each  of  three  con- 
secutive days.     This  makes  certain  the  destruction  of 


Fig.  21. — Instrument  sterilizer. 

all  spores.     Surgical  dressings  may  also  be  sterilized  in 
this  form  of  sterilizer. 

(5)  The  destructive  action  of  steam  can  be  enor- 
mously increased  by  employing  it  under  pressure.  For 
this  a  special  form  of  apparatus  is  required.  It  is  im- 
possible to  heat  water,  in  an  open  vessel  or  in  an  Arnold 
sterilizer,  to  more  than  212°  F.  As  soon,  however,  as 
we  heat  the  water  in  a  tightly  closed  vessel,  which  will 
not  allow  the  steam  to  escape,  we  can  raise  the  tempera- 
ture beyond  this.  The  higher  the  pressure  of  the  steam, 
the  higher  the  temperature.  It  is  mainly  because  of  this 
fact  that  the  use  of  steam  under  pressure  is  so  much 
more  effective  in  sterilization  than  the  use  of  live 
steam  not  under  pressure.  Another  reason  is  the 


46 


APPLIED    BACTERIOLOGY  FOR   NURSES 


greater  penetration  secured  by  having  the  steam  under 
pressure. 

The  accompanying  figure  shows  a  common  type  of 
steam  sterilizer. 


Fig.  22. — A  pressure  steam  sterilizer.  The  steam  jacket  entirely 
surrounds  the  chamber,  to  which  the  steam  is  admitted  through  a 
valve.  Pressure  may  be  continued  on  the  jacket  while  the  dressings 
are  removed.  The  safety-valve  is  set  to  relieve  at  15  pounds. 


The  teacher  should  demonstrate  the  use  of  heat  for  sterilization 
by  inoculating  six  broth  tubes  with  a  well  sporulated  culture  of  hay 
bacilli,  and  heating  two  in  an  Arnold  sterilizer  for  five  minutes,  two 
others  in  a  pressure  steam  sterilizer  for  five  minutes  (pressure  of 
15  pounds),  leaving  two  unheated.  After  this,  all  six  tubes  are 
placed  in  an  incubator  over  night. 


CHAPTER  VIII 

THE  RELATION  OF  BACTERIA  TO  DISEASE.    INFLAM- 
MATION 

WE  have  already  called  attention  to  the  fact  that 
only  a  small  proportion  of  the  known  bacteria  are 
producers  of  disease,  i.  e.,  are  pathogenic.  In  order 
to  prove  positively  that  a  disease  is  due  to  a  certain 
bacterium  it  is  absolutely  necessary  that  this  bacterium 
be  always  found  in  the  disease.  Furthermore,  it  must 
be  possible  to  reproduce  the  same  disease  by  the  injec- 
tion of  pure  cultures  of  the  bacterium,  and  from  the 
diseased  tissues  thus  produced  it  must  be  possible  to 
again  isolate  the  germ. 

The  manner  in  which  the  various  bacteria  produce 
disease,  their  entrance  into  the  body,  the  part  of  the 
body  commonly  attacked,  all  these  differ  considerably 
with  the  different  micro-organisms.  Some,  like  the 
bacillus  of  diphtheria  and  the  bacillus  of  tetanus  (lock- 
jaw), secrete  very  powerful  poisons,  and,  while  these 
bacteria  do  not  themselves  penetrate  deep  into  the  body 
tissues,  their  poison  is  absorbed  and  gives  rise  to  severe 
symptoms.  In  the  case  of  other  bacteria,  for  example, 
the  tubercle  bacillus,  the  germs  penetrate  deep  into  the 
body  tissues  and  there  multiply.  In  their  growth  they 
give  off  poisons  which  cause  the  gradual  destruction  of 
the  tissues  in  which  they  lodge.  In  this  way  the  tubercle 
bacillus  causes  large  parts  of  the  lung  to  be  destroyed  or 
bones  to  be  eaten  away,  etc. 

47 


48  APPLIED   BACTERIOLOGY   FOR  NURSES 

Most  germs,  for  some  obscure  reason,  affect  by  prefer- 
ence certain  parts  of  the  body.  The  typhoid  bacillus 
usually  lodges  in  the  wall  of  the  small  intestine;  the 
meningococcus  prefers  the  lining  of  the  brain  and  spinal 
cord;  the  gonococcus  is  very  prone  to  attack  the  mucous 
membrane  lining  the  genital  organs,  and  also  the  con- 
junctival  membrane  (outer  lining  of  the  eye).  The 
pneumococcus  affects  chiefly  the  respiratory  organs; 
the  diphtheria  bacillus,  the  throat  and  nasal  passages. 

The  extent  and  kind  of  disease  produced  by  the  same 
bacterium  also  varies  greatly.  This,  of  course,  depends 
largely  on  the  size  of  the  dose  introduced,  but  also 
on  the  degree  of  resistance  of  the  patient.  We  shall 
speak  of  this  in  a  moment. 

The  more  important  pathogenic  bacteria  are  the 
bacillus  of  tuberculosis,  the  typhoid  bacillus,  diphtheria 
bacillus,  dysentery  bacillus,  spirillum  of  cholera,  the 
pneumococcus,  the  streptococcus,  the  staphylococcus 
pyogenes,  the  meningococcus,  the  gonococcus,  the  bacil- 
lus of  tetanus,  of  anthrax,  of  glanders,  of  bubonic 
plague,  and  of  malignant  edema.  The  germs  of  malaria, 
syphilis,  and  sleeping-sickness  are  tiny  organisms  called 
protozoa.1  The  germs  of  ringworm  and  of  barbers'  itch 
are  fungi.1  The  germs  of  smallpox,  chickenpox,  scarlet 
fever,2  measles,  yellow  fever,  and  hydrophobia  have  not 
yet  been  discovered,  though  there  is  no  doubt  whatever 
of  the  germ  nature  of  these  diseases.  Several  alleged 
"cancer  germs"  have  been  described,  but  not  only  has 
their  relation  to  cancer  not  yet  been  proved,  but  there 
is  still  considerable  doubt  whether  cancer  is  a  germ 

1  See  Definitions,  page  13. 

2  See  page  120. 


THE   RELATION   OF   BACTERIA  TO   DISEASE  49 

disease.  Some  authorities  claim  that  pellagra  is  a  germ 
disease,  but  the  weight  of  evidence  appears  against  this 
belief.  On  the  other  hand,  acute  articular  rheumatism  is 
generally  regarded  as  a  germ  disease,  most  bacteriologists 
believing  that  the  specific  germ  has  not  yet  been  identified. 

INFLAMMATION 

Inflammation  is  described  as  "a  local  reaction  caused 
by  agents  which  have  produced  tissue  injury."  Among 
the  causes  of  inflammation  we  find  blows,  poisonous  sub- 
stances like  snake  venom,  acids,  or  other  irritant  chemical 
compounds,  excessive  heat  or  cold,  and,  finally,  perhaps  the 
most  important  of  all,  bacteria.  The  degree  of  injury 
produced  depends  on  a  number  of  factors.  In  the  inflam- 
mation due  to  bacteria  it  depends  on  the  number  of  bac- 
teria introduced,  the  virulence  of  the  organisms,  the  length 
of  time  they  remain,  and  on  the  resistance  of  the  infected 
tissues. 

The  first  response  on  the  part  of  the  body  consists  in  a 
dilatation  of  the  blood-vessels  of  the  affected  region  and 
a  quickening  of  the  blood  flow.  This  quickening,  how- 
ever, is  soon  followed  by  a  slowing  of  the  blood-current, 
and  the  passage  through  the  wall  of  the  blood-vessels 
of  blood-serum  and  white  blood-corpuscles  (leukocytes). 
Sometimes  the  amount  of  blood-serum  is  small,  but  the 
number  of  white  blood-cells  large;  at  other  times  the 
reverse  may  be  true.  If  the  inflammation  is  severe, 
red  blood-cells  also  pass  through  the  wall  of  the  blood- 
vessels. 

Let  us  see  what  takes  place  when  some  staphylococci 
invade  the  deeper  parts  of  the  skin  and  give  rise  to  a  boil. 
As  soon  as  these  germs  have  entered  they  act  as  an  irritant 

4 


50  APPLIED    BACTERIOLOGY   FOR   NURSES 

to  the  various  cells  around  them,  just  as  a  tiny  particle 
of  dust  irritates  the  eye.  All  about  the  body  cells  are  the 
capillaries,  flowing  through  which  are  the  various  blood- 
cells  suspended  in  a  watery  fluid  called  the  blood-plasma. 
The  irritation  produced  by  the  staphylococci  is  at  once 
felt  by  the  blood-stream,  and  for  a  short  time  it  flows 
faster  and  the  blood-vessels  dilate,  as  though  in  this  way 
to  wash  the  irritant  away.  Undoubtedly  there  are  many 
times  when  this  suffices,  especially  when  the  irritating 
agent  acts  for  only  a  short  time  and  is  very  mild.  If  this 
is  not  the  case  the  blood-current  slows,  and  now  an  inter- 
esting process  begins.  The  white  blood-corpuscles  (leuko- 
cytes) make  their  way  through  the  wall  of  the  blood-vessel 
and  hunt  out  the  offending  bacteria.  They  act  exactly 
as  though  they  were  police  officers  going  after  a  law 
breaker.  Accompanying  the  leukocytes  is  a  flow  of  serum 
into  the  tissues,  and  this,  as  we  shall  see,  contains  sub- 
stances which  aid  the  leukocytes  in  their  fight.  If  one 
watches  this  process  under  a  microscope  one  can  see  the 
white  blood-cells  (leukocytes)  actually  engulf  the  invading 
bacteria,  sometimes  taking  up  ten  or  a  dozen  bacteria.1 
But  the  fight  is  not  yet  over.  It  is  all  a  question  now 
whether  there  are  enough  leukocytes  to  combat  the  bac- 
teria, and  whether  the  leukocytes  can  destroy  the  bac- 
teria which  they  have  engulfed.  As  a  rule,  some  of 
the  leukocytes,  instead  of  destroying  the  bacteria  wrhich 
they  have  "swallowed,"  are  themselves  destroyed  by  the 
bacteria. 

Meantime,  while  some  of  the  leukocytes  are  busy  fighting 
the  bacteria,   other  cells  are  busy  massing  themselves 

1  In  connection  with  this  the  student  should  study  Fig.  37,  which 
shows  a  leukocvte  filled  with  bacteria. 


THE    RELATION    OF    BACTERIA   TO    DISEASE  51 

solidly  around  the  scene  of  conflict,  forming  a  dense  ring  or 
wall  which  shuts  off  the  fighters  from  the  rest  of  the  body. 
Inside  the  ring  many  of  the  combatants  are  killed,  so  that, 
in  addition  to  living  bacteria  and  living  leukocytes,  there 
is  now  an  accummulation  of  cellular  and  bacterial  debris. 
When  the  inflammation  has  proceeded  in  this  way  we  have 
an  abscess.  The  pus  in  an  abscess  is  composed  of  leuko- 
cytes, broken-down  tissue  cells,  bacteria,  fibrin,  serum, 
and  debris. 

However,  the  inflammation  may  take  a  somewhat  dif- 
ferent course — an  abscess  does  not  always  result.  The 
course  depends  mainly  on  the  nature  and  virulence  of  the 
invading  bacterium,  the  part  of  the  body  invaded,  and  the 
resistance  of  the  patient.  Thus  it  may  happen  that  the 
invading  organisms  are  so  virulent  or  so  numerous  that 
before  the  leukocytes  and  other  cells  have  completed  their 
wall  about  the  scene  of  conflict  the  invading  bacteria  have 
extended  into  the  tissues  far  beyond.  Again  and  again  the 
leukocytes  and  other  body  cells  gather  and  attempt  to 
localize  the  conflict,  the  inflammation  meantime  involving 
a  large  area  of  tissue.  This  kind  of  inflammation  is  spoken 
of  as  a  cellulitis  or  a  purulent  infiltration;  it  is  often  due  to 
the  streptococcus. 

In  typhoid  fever  we  meet  with  another  type  of  inflam- 
mation, namely,  an  ulceration.  In  this  disease  we  have  a 
localization  of  typhoid  bacilli  in  certain  lymph-follicles 
known  as  "Peyer's  patches,"  situated  in  the  wall  of  the 
small  intestine.  Instead  of  forming  circumscribed  ab- 
scesses, the  inflammation  here  produces  ulcers  opening  on 
the  inner  surface  of  the  gut.  In  other  words,  an  ulcer  is 
an  abscess  whose  outer  wall  is  missing. 

When  bacteria  invade  the  pleura  a  variety  of  inflam- 


52  APPLIED    BACTERIOLOGY    FOR   NURSES 

matory  reactions  may  occur.  Thus  we  may  have  a 
"dry  pleurisy."  In  this  form  of  inflammation  the  passage 
of  the  defending  leukocytes  is  accompanied  by  the  exuda- 
tion of  large  amounts  of  fibrin,  as  though  nature  deliber- 
ately intended  to  glue  the  two  opposing  pleural  surfaces 
together.  Or  we  may  have  a  "pleurisy  with  effusion," 
in  which  the  number  of  defending  leukocytes  which  pass 
out  of  the  blood-vessels  is  relatively  small,  while  the  quan- 
tity of  blood-serum  which  passes  out  is  enormous.  One 
cannot  help  thinking  that  this  is  intended  to  dilute  the 
irritant  which  has  caused  the  inflammation.  Finally,  we 
meet  with  cases  in  which  both  the  number  of  leukocytes 
and  the  amount  of  serum  are  large,  forming  really  a  thick 
pus.  This  form  of  pleurisy  constitutes  an  "empyema." 

In  some  instances,  as  in  the  case  of  the  staphylo- 
coccus  boil  described  above,  the  bacterium  itself  invades 
the  tissues  and  constitutes  the  irritant  which  gives  rise 
to  the  inflammation.  In  other  cases  the  inflammation 
is  produced  mainly  by  poisons  given  off  by  the  bac- 
teria. The  latter  is  well  seen  in  diphtheria,  where  the 
bacilli  remain  on  the  tonsil  and  the  poison  (diphtheria 
toxin)  causes  inflammatory  changes  in  various  parts  of  the 
body. 

In  case  the  inflammation  is  slight,  both  the  serum  and 
the  leukocytes  which  have  passed  out  of  the  blood-vessels 
may  re-enter  the  circulation.  When  the  cells  are  more 
numerous  they  may  first  undergo  a  kind  of  digestion 
and  then  be  absorbed  by  certain  scavenger  cells  of  the 
body. 

When  pus  is  formed  it  usually  works  its  way  to  the  sur- 
face and  is  discharged  either  through  external  openings  or 
into  cavities  of  the  body. 


THE   RELATION   OF   BACTERIA   TO   DISEASE  53 

Injured  tissue  cells  may  recover  if  the  inflammation  is 
not  severe,  or  they  may  soften,  break  down,  and  be  re- 
moved. 

When  the  body  has  actually  been  destroyed  as  the 
result  of  an  inflammation,  we  find  that  there  is  almost 
always  the  formation  of  connective  tissue  to  take  the  place 
of  that  destroyed.  This  constitutes  what  is  subsequently 
known  as  a  scar. 


CHAPTER  IX 
THE  TRANSMISSION  OF  INFECTIOUS  DISEASES 

No  theory  has  been  more  generally  accepted,  both 
by  the  medical  profession  and  the  public  at  large,  than 
the  belief  that  infectious  diseases  are  commonly  trans- 
mitted by  clothing,  baggage,  money,  rags,  and  innumer- 
able other  articles,  which  are  supposed  to  convey  patho- 
genic organisms  in  their  active  state  from  one  person 
to  another.  These  alleged  agents  are  known  as  "fomites." 
Since  the  discoveries  of  Pasteur  and  Koch,  and  particu- 
larly during  the  past  ten  or  fifteen  years,  practical 
sanitarians  have  been  slowly  but  surely  accumulating 
conclusive  evidence  of  the  fallacy  of  the  fomites  theory. 
Not  so  long  ago  malaria  was  attributed  to  the  presence 
of  ' 'miasma,"  or  poisonous  vapors  emanating  from 
swamps;  now  we  know  that  this  disease  is  transmitted 
from  man  to  man  through  the  bite  of  a*  mosquito.  Up 
to  within  a  few  years,  yellow  fever  was  held  to  be  trans- 
mitted by  "fomites,"  and  the  medical  history  of  the 
South  is  rich  in  statistics  which  presume  to  offer  con- 
clusive proof  that  the  clothing  of  those  who  had  been 
exposed  to  yellow  fever  was  responsible,  at  various  times, 
for  outbreaks  of  this  disease.  Yet  we  now  know  that 
yellow  fever  is  transmitted  only  through  the  bite  of  a 
particular  species  of  mosquito.  Satisfactory  evidence 
has  been  given  us  that  plague,  which  was  believed  to  be 
caused  by  almost  anything  in  the  nature  of  "fomites," 

54 


THE   TRANSMISSION   OF   INFECTIOUS   DISEASES        55 

is  conveyed  to  man  by  the  rat,  through  the  medium  of 
fleas  which  infest  these  animals.  A  few  years  ago  it 
would  have  been  difficult  to  find  a  text-book  which  did 
not  in  positive  terms  state  that  typhus  fever  is  trans- 
mitted by  clothing,  baggage,  and  other  articles.  Yet 
careful  investigations,  particularly  the  recent  work  of 
Goldberger  and  Anderson  in  Mexico,  proves  that  the 
disease  is  transmitted  by  the  body  louse  and  not  by 
fomites.  With  regard  to  two  common  diseases  of  child- 
hood, namely,  measles  and  scarlet  fever,  public  health 
authorities  are  coming  more  and  more  to  believe  that 
desquamation  of  the  skin  is  a  negligible  factor,  and  that 
these  diseases  are  conveyed  from  person  to  person  by  the 
infected  discharge  of  the  mucous  membrane  involved. 

It  is  only  within  comparatively  recent  years  that  we 
have  appreciated  the  importance  and  danger  of  mild, 
ambulant,  or  irregular  cases  of  infectious  diseases,  and 
the  frequency  with  which  they  occur.  They  are  un- 
doubtedly one  of  the  most  common  and  dangerous  fac- 
tors in  the  transmission  of  infection  because  they  often 
pass  unrecognized.  More  recently  we  have  learned  of 
"carriers,"  or  persons  who,  while  themselves  well, 
harbor  the  specific  micro-organism,  and  may  transmit 
it  to  others.  These  undoubtedly  play  an  important 
role  in  the  spread  of  infectious  diseases. 

All  these  observations  have  served  to  discredit  the 
fomites  theory,  and,  while  there  is  no  doubt  that  in  some 
rare  instances  clothing,  rags,  books  and  toys,  etc.,  may 
act  as  a  medium  of  infection,  we  should  devote  our  at- 
tention principally  to  the  usual  or  common  means  of 
infection.  The  knowledge  we  now  possess  on  this  sub- 
ject proves  that  infectious  diseases  are  transmitted  by 


56  APPLIED   BACTERIOLOGY  FOR   NURSES 

persons  rather  than  by  things — by  contact  with  others, 
by  certain  discharges  of  those  who  are  infected,  and  by 
insects  and  vermin. 

TERMINAL  FUMIGATION 

The  question  which  at  once  arises  is  as  to  the  need  of 
terminal  room  fumigation  in  infectious  diseases.  If  such 
diseases  are  not  carried  by  fomites,  why  go  to  all  the 
trouble  of  room  fumigation?  As  a  matter  of  fact,  a  num- 
ber of  progressive  health  departments  have  discontinued 
most  of  the  terminal  fumigations  formerly  done  after  con- 
tagious diseases.  Among  these  may  be  mentioned  the 
health  departments  of  Providence,  New  York  City,  Bos- 
ton, and  Milwaukee.  In  New  York  a  very  interesting 
experiment  was  conducted  in  1914  and  1915,  fumigation 
being  discontinued  in  some  of  the  boroughs  and  continued 
in  the  others.  No  increase  in  the  prevalence  of  the  con- 
tagious disease  followed  the  discontinuance  of  terminal 
fumigation.  It  should  be  understood,  however,  that  in 
discontinuing  fumigation,  increased  stress  is  laid  on  other 
and  more  efficient  methods  of  disinfection,  namely, 
thorough  cleaning,  fresh  air  and  sunlight,  and  particularly 
renovation  (i.  e.,  repainting  and  repapering)  when  neces- 
sary. Moreover,  the  reader  must  bear  in  mind  that  fumi- 
gation is  still  necessary  in  such  diseases  as  typhus  (to  kill 
vermin),  yellow  fever  (to  kill  mosquitoes),  and  plague 
(to  kill  rats). 

INSECTS  AS  CARRIERS  OF  INFECTIOUS  DISEASES 

Before  leaving  this  subject,  it  will  be  well  to  devote  a 
little  attention  to  the  r6le  played  by  insects  and  vermin 
in  the  transmission  of  infectious  diseases.  This  r6le  may 


THE   TRANSMISSION   OF   INFECTIOUS   DISEASES       57 

be  non-specific  (merely  mechanical)  or  specific.  Thus, 
when  typhoid  bacilli  are  carried  by  flies  from  some 
infected  feces  to  a  pitcher  of  milk,  the  transmission  is 
merely  a  mechanical  transfer  of  the  bacilli  on  the  fly's 
legs  and  proboscis.  It  does  not  matter  what  species  of 
fly  is  concerned;  in  fact,  it  need  not  be  a  fly  at  all, 
but  some  other  insect.  The  transmission  of  plague 
from  infected  rats  to  man  is  probably  of  this  kind,  and, 
as  far  as  our  present  knowledge  goes,  so  is  the  trans- 
mission of  typhus  fever  by  lice. 

Quite  different  are  the  circumstances  governing  the 
specific  transmission.  Common  examples  of  these  are 
malaria,  yellow  fever,  and  sleeping  sickness.  When 
malaria  is  carried  from  one  person  to  another  by  the 
mosquito  it  is  found  that  this  is  always  a  mosquito  of 
the  species  Anopheles.  The  ordinary  Culex  mosquito 
is  unable  to  effect  the  transmission.  In  malaria,  as  we 
have  already  seen,  the  tiny  parasite  sucked  up  in  the 
patient's  blood  by  the  biting  mosquito  undergoes  cer- 
tain characteristic  changes,  and  it  is  only  after  these 
changes  have  been  completed  that  the  mosquito  is  able 
to  infect  another  person.  But  for  some  unknown  reason 
these  changes  occur  only  in  the  stomach  of  Anopheles 
and  not  in  other  species  of  mosquitos.  In  yellow  fever 
and  sleeping-sickness  conditions  are  entirely  analogous, 
in  the  former  a  species  of  mosquito  known  as  Aedes  is 
required,  and  in  the  latter'  a  species  of  biting  fly  know 
as  "tsetse  fly"  effects  the  transmission.  According  to 
Rosenau  poliomyelitis  is  transmitted  in  a  specific  non- 
mechanical  manner  by  the  bite  of  the  common  stable 

fly. 


58  APPLIED    BACTERIOLOGY   FOR   NURSES 

The  following  is  a  partial  list  of  insects  which  carry 
disease: 

Yellow  fever  mosquito  (Aedes  calopus),  formerly  called 
Stegomyia  calopus. 

Malaria  mosquito  (Anopheles  maculipennis) . 

House  fly  (Musca  domestica)  may  carry  organisms  of 
typhoid  fever,  cholera,  and  other  diseases. 

Tsetse  fly  (Glossina  palpalis)  transmits  sleeping-sickness. 

Tick  (Dermacentor  andersoni)  transmits  Rocky  Mountain 
spotted  fever. 

Tick  (Margaropus  annnlatus)  transmits  Texas  fever. 

Stable  fly  (Stomoxys  calcitrans)  may  transmit  infantile 
paralysis  (poliomyelitis) . 

Flea  (Xenopsylla  cheopis),  a  carrier  of  bubonic  plague. 

Body  louse  (Pediculus  vestimenti)  transmits  typhus 
fever. 

Bedbug  (Cimex  lectularius)  transmits  relapsing  fever. 

So  far  as  the  nurse  is  concerned,  the  above  facts  call 
for  careful  attention  to  flies,  mosquitoes,  fleas,  bedbugs, 
lice,  and  other  vermin  about  every  case  of  infectious  dis- 
ease. 


CHAPTER  X 

QUARANTINE  IN  THE  CONTROL  OF  INFECTIOUS 
DISEASES 

QUAKANTINE,  or  isolation,  as  a  method  of  controlling  the 
spread  of  infectious  diseases  dates  from  the  efforts  made  by 
Venice  in  1403  to  check  the  spread  of  the  dreaded  "Black 
Death/1  All  passengers  arriving  on  ships  at  the  port  of 
Venice  were  isolated  in  a  special  hospital  situated  on  a 
small  island  adjoining  the  city.  Here  they  were  kept  for 
forty  days  before  being  allowed  to  enter  the  city.  This, 
then,  is  the  origin  of  the  term  "quarantine,"  quadraginta 
meaning  forty.  With  increasing  knowledge  of  the  trans- 
mission of  infectious  diseases  there  has  come  a  change  in 
our  methods  of  dealing  with  the  spread  of  these  diseases, 
and  this  has  markedly  affected  the  duration  of  the  period 
of  isolation  enforced  by  health  authorities. 

To  a  large  extent  the  minimum  period  of  enforced 
isolation  has  been  arrived  at  as  the  result  of  bacteriologic 
investigations  and  animal  experimentation.  In  addition 
to  this  we  are  guided  by  disappearance  of  fever,  freedom 
from  crusts  or  scabs,  and  the  absence  of  catarrhal  or  sup- 
purative  processes. 

The  period  of  isolation  required  in  different  diseases 
varies  considerably  in  different  cities.  In  describing  con- 
ditions as  they  prevail  in  New  York  City  at  the  present 
time,  therefore,  we  aim  merely  to  give  the  student  a 
general  idea  of  the  considerations  which  guide  health 
officials  in  their  action. 


60  APPLIED   BACTERIOLOGY   FOR   NURSES 

A  patient  ill  with  diphtheria  in  New  York  City  must  be 
kept  isolated  for  at  least  two  weeks,  and  even  then  the 
patient  may  not  be  discharged  until  after  two  consecutive 
negative  cultures  have  been  obtained  from  both  nose  and 
throat. 

In  contrast  to  this  logical  termination  of  isolation  in 
diphtheria  by  means  of  cultures,  the  period  of  isolation 
in  scarlet  fever  is  very  nearly  arbitrary.  In  New  York 
City  isolation  is  maintained  until  at  least  thirty  days  from 
the  appearance  of  the  rash.  Desquamation  is  no  longer 
held  to  be  of  any  special  significance  in  the  conveyance 
of  infection.  Suppurative  processes,  on  the  other  hand, 
are  more  seriously  regarded  and  often  serve  to  confine  the 
patient  for  several  weeks  beyond  the  period  named. 
It  is  possible  that  the  recent  observations  of  Mallory 
(page  120)  will  furnish  a  more  definite  basis  for  fixing  the 
duration  of  isolation  necessary  in  this  disease. 

In  measles  the  patient  may  be  released  from  isolation 
and  allowed  to  return  to  school  five  days  after  the  appear- 
ance of  the  rash.  Formerly  the  period  of  isolation  was 
much  longer,  but  experiments  on  monkeys  by  Anderson 
and  Goldberger  showed  that  five  days  was  sufficient.  To 
be  sure,  this  applies  only  to  patients  who  are  free  from 
serious  catarrhal  or  pneumonic  complications. 

In  typhoid  fever  there  is  no  fixed  time  limit  to  the 
period  of  isolation.  Stool  examinations  for  typhoid  bacilli 
should  be  made  after  the  patient's  temperature  has  been 
normal  for  at  least  ten  days.  In  the  case  of  food  handlers 
(cooks,  waiters,  dairymen,  etc.)  return  to  work  is  pro- 
hibited so  long  as  the  stools  contain  typhoid  bacilli. 
Accordingly,  at  least  two  consecutive  stool  examinations 
made  a  week  apart  should  fail  to  show  typhoid  bacilli 


QUARANTINE  IN  CONTROL  OF  INFECTIOUS  DISEASES     61 

before  such  an  individual  may  be  allowed  to  return  to  his 
work. 

In  smallpox  the  patient  is  invariably  removed  to  the 
isolation  hospital  of  the  Department  of  Health.  Isolation 
is  maintained  until  all  scabs  have  disappeared,  including 
the  deep-seated  "seeds"  beneath  the  epidermis  of  the 
soles  of  the  feet. 

In  epidemic  cerebrospinal  meningitis  isolation  is  main- 
tained for  fourteen  days,  for  it  has  been  found  that  menin- 
gococci  in  the  nasopharynx  of  convalescents  are  very  rare 
after  the  twelfth  or  fourteenth  day.  Whenever  facilities 
permit  healthy  contact  carriers  should  be  sought  out  and 
isolated. 

In  acute  anterior  poliomyelitis  (infantile  paralysis)  the 
minimum  period  of  quarantine  is  six  weeks,  a  period  fixed 
largely  as  the  result  of  experimental  work  on  animals. 

In  yellow  fever  it  is  now  well  established  that  the  pa- 
tient's blood  remains  infective  about  three  days.  More- 
over, after  having  been  bitten  by  an  infected  mosquito  it 
requires  about  five  days  for  symptoms  to  develop.  (See 
also  page  128.)  Isolation,  therefore,  is  relatively  short 
and  amounts,  moreover,  only  to  screening  the  patient  from 
mosquitoes. 

In  typhus  fever  the  recent  bacteriologic  work  of  Plotz 
indicates  that  isolation  need  not  be  maintained  for  much 
beyond  the  return  of  the  fever  to  normal.  The  greatest 
danger  period  would  appear  to  be  four  or  five  days  pre- 
ceeding  the  crisis,  for  at  that  time  the  typhus  bacilli 
are  most  numerous  in  the  patient's  blood.  Inasmuch  as 
the  disease  is  spread  by  lice,  care  should  be  taken  to  de- 
stroy all  lice  by  thorough  washing  of  the  patient  and  dis- 
infection of  his  clothing  and  other  belongings. 


62  APPLIED   BACTERIOLOGY   FOR   NURSES 

In  cholera  the  termination  of  isolation  rests  solely  on  the 
result  of  the  bacteriologic  examination  of  the  stools.  A 
minimum  requirement  is  two  consecutive  negative  stools 
taken  at  intervals  of  five  days  after  convalescence  is  com- 
plete. 

In  whooping-cough  a  more  definite  routine  is  now  being 
developed,  for  the  disease  is  believed  to  be  transmitted 
mainly  in  the  early  days.  The  whooping-cough  bacilli 
are  scarcely  found  after  the  second  week,  so  that  isolation 
may  be  relaxed  two  weeks  after  the  onset  of  the  spasmodic 
cough.  Nevertheless,  when  taken  out,  the  child  should 
be  kept  strictly  away  from  other  children  until  the  spas- 
modic cough  has  entirely  disappeared. 

In  German  measles  isolation  is  usually  fixed  at  one 
week,  in  mumps  (parotitis)  until  all  swelling  is  gone,  and 
in  chickenpox  (varicella)  until  all  the  scabs  are  off. 


CHAPTER  XI 

IMMUNITY 

IT  is  well  known  that  certain  infectious  diseases  occur 
naturally  only  among  some  of  the  lower  animals,  and 
do  not  affect  man;  while,  conversely,  others  appear  to 
attack  only  man.  Among  the  latter  may  be  mentioned 
typhoid  fever,  syphilis,  gonorrhea.  In  speaking  of  the 
resistance  evidently  possessed  by  certain  individuals  or 
certain  species,  we  make  use  of  the  term  natural  im- 
munity. Thus,  chickens  and  frogs  possess  a  natural 
immunity  against  tetanus  (lock-jaw);  dogs,  a  natural 
immunity  against  anthrax;  goats,  a  natural  immunity 
against  tuberculosis,  and  man,  a  natural  immunity 
against  certain  diseases  of  cattle.  This  natural  im- 
munity, however,  is  not  absolute.  Chickens,  for  example, 
can  be  infected  with  tetanus  if  the  body  is  chilled,  and 
frogs  can  be  made  susceptible  to  tetanus  by  keeping 
them  unduly  warm. 

Another  form  of  immunity  is  that  observed  in  indi- 
viduals who  have  had  one  attack  of  a  particular  infec- 
tion; thereafter  they  are  practically  safe  from  a  second 
attack.  These  individuals  are  said  to  possess  an  acquired 
immunity.  This  form  of  immunity  is  well  illustrated  in 
scarlet  fever,  measles,  small-pox,  yellow  fever.  Often 
this  immunity  lasts  throughout  the  lifetime  of  the  indi- 
vidual, though  there  are  exceptions. 


64  APPLIED    BACTERIOLOGY    FOR   NURSES 

In  studying  this  acquired  immunity,  Pasteur,  a 
French  scientist  who  lived  1822  to  1895,  conceived  the 
idea  of  artificially  producing  an  attack  of  a  given  infec- 
tion in  order  to  protect  the  individual  against  another 
attack.  He  realized  that  it  was  necessary,  however,  to 
so  control  matters  that  the  original  attack  should  run  a 
very  mild  course  and  not  endanger  the  life  of  the  indi- 
vidual. After  considerable  experimental  labor,  Pasteur 
found  that  this  could  be  accomplished  by  artificially 
weakening  the  bacteria  with  which  the  original  attarck 
of  the  disease  was  produced.  Subsequently  Salmon  and 
Smith,  in  this  country,  showed  that  it  was  not  necessary 
to  produce  even  a  mild  attack  of  the  disease  by  the  injec- 
tion of  living  bacteria,  but  that  the  injection  of  dead 
bacteria  would  produce  an  immunity  against  that  par- 
ticular infection. 

Acquired  immunity,  whether  caused  by  a  previous 
natural  attack  of  the  disease,  or  artificially  by  the  inocu- 
lation of  bacteria,  is  always  strictly  specfic,  that  is,  the 
protection  extends  only  to  the  particular  disease  which 
has  previously  occurred  or  whose  germs  have  previously 
been  injected.  An  attack  of  scarlet  fever  protects  only 
against  scarlet  fever,  but  not  against  measles.  Inoculat- 
ing an  individual  with  typhoid  bacilli  protects  him  only 
against  typhoid  fever,  but  not  against  dysentery,  plague, 
cholera,  etc.  This  acquired  immunity  is  often  trans- 
mitted from  mother  to  offspring,  transmission  being 
effected  mainly,  according  to  Famulener,  through  the 
colostrum.  This  shows  the  importance  of  placing  baby 
to  the  mother's  breast  soon  after  birth. 

Before  examining  into  the  nature  of  this  very  specific 
form  of  immunity,  it  will  be  well  to  call  attention  to 


IMMUNITY  65 

certain  important  means  by  which  the  body  defends 
itself  against  bacterial  invasion  in  general.  Many  of 
these  are  so  commonplace  that  their  significance  is  often 
overlooked : 

(1)  The  protection  afforded  to  the  body  by  the  un- 
broken skin  is  undoubtedly  one  of  the  most  important 
means  of  defence.     It  is  well  to  remember  this,  and 
especially  to  bear  in  mind  that  we  say  "unbroken"  skin. 
In  the  sterilization  of  the  skin  prior  to  a  surgical  opera- 
tion a  great  deal  of  harm  is  sometimes  done  by  too 
vigorous  scrubbing  or  the  application  of  too  concen- 
trated disinfectants. 

(2)  A  similar  protection,   though  less  powerful,  is 
afforded  by  intact  and  healthy  mucous  membranes. 
Any  condition  injuriously  affecting  these  renders  the 
body  more  liable  to  bacterial  invasion.     This  is  well 
illustrated  by  the  frequency  with  which  an  attack  of 
measles   (which  affects  the  mucous  membranes  to  a 
marked  degree)  is  the  starting-point  of  other  and  more 
serious  infections. 

(3)  TKe~1icid    gastric    juice   undoubtedly  destroys 
large  numbers  of  bacteria  which  are  swallowed.    Dis- 
orders of  digestion  may,  therefore,  constitute  the  decid- 
ing factor  in  determining  a  bacterial  invasion,  especially 
of  the_intestinal  tract. 

(4)  It  has  been  found  that  fresh  blood-serum  is  able 
to  kill  a  considerable  number  of  bacteria,  and  this, 
therefore,  constitutes  another  mode  of  defence  against 
bacterial  invasion. 

(5)  The  white  blood-cells,  or  leukocytes,  as  they  are 
called,  appear  to  be  designed  especially  to  destroy  in- 


66  APPLIED   BACTERIOLOGY   FOR   NURSES 

vading  bacteria.  These  cells  take  hold  of,  or  rather 
engulf,  the  bacteria  and  digest  them.1 

(6)  Still  another  mode  of  defence  is  seen  in  what 
takes  place  in  abscesses.  When  these  are  examined,  it  is 
found  that  the  body  has  built  a  wall  around  the  infected 
area,  thus  shutting  off  the  bacteria  and  their  poisonous 
products  from  the  rest  of  the  body. 

Returning  now  to  the  mechanism  of  the  specific 
acquired  immunity  discussed  above,  we  find  that,  in 
response  to  the  invasion  by  pathogenic  bacteria,  the 
body  manufactures  certain  specific  substances  designed 
to  destroy  the  invaders  or  to  neutralize  their  poisonous 
products. 

These  antagonistic  substances  are  spoken  of  as  anti- 
bodies. The  important  antibodies  thus  far  known  are 
as  follows: 

(1)  Antitoxins. 

(2)  Bacteriolysins,  hemolysins  (cytolysins). 

(3)  Agglutinins. 

(4)  Opsonins. 

(5)  Precipitins. 

(6)  Antiferments. 

Antitoxins. — When  an  animal  is  injected  with 
gradually  increasing  doses  of  toxin — e.  g.,  with  diph- 
theria toxin — it  will  be  found  that  after  a  time  the  animal 
withstands  doses  of  the  poison  which  would  suffice  to 
kill  hundreds  of  animals  not  so  treated.  This  was  done 
in  1890  by  von  Behring,  who  found  that  the  blood  of  the 
treated  animals  contained  something  which  neutralized 

1  Certain  substances,  such  as  alcohol,  also  exposure  to  cold,  make 
the  leukocytes  sluggish,  so  that  drunkeness  on  the  part  of  an  in- 
dividual or  exposure  to  cold  often  lead  to  bacterial  invasion. 


IMMUNITY  67 

the  diphtheria  poison  and  rendered  it  harmless.  It 
was  natural  to  see  whether  this  blood-serum  could  be 
used  to  treat  other  animals  which  had  previously  been 
injected  with  diphtheria  poison,  and  on  doing  this  von 
Behring  found  that  the  serum  thus  used  was  able  to  save 
the  animals  from  death.  The  action  of  the  substance  in 
the  serum  which  counteracted  the  effect  of  the  poison 
was  found  to  be  exactly  like  that  of  an  alkali  on  an  acid, 
i.  e.,  it  neutralized  the  poison.  It  was,  therefore,  called 
an  antitoxin,  meaning  against  toxin.  The  antitoxic 
serum  from  an  animal  treated  with  toxin  does  not  differ 
in  appearance  from  that  of  a  normal  untreated  animal. 
And  even  when  tested  chemically,  but  little  difference 
can  be  discovered  between  the  two.  In  order,  therefore, 
to  recognize  the  presence  of  this  antitoxin  in  the  serum, 
and  especially  in  order  to  measure  its  amount,  we  must 
test  it  in  animals,  and  see  how  small  a  quantity  of  anti- 
toxic serum  will  save  an  animal  after  injection  with  a 
certain  amount  of  diphtheria  toxin.  When  guinea-pigs 
are  used  for  the  test,  it  may  be  found  that  T^nf  cm. 
of  the  antitoxic  serum  will  often  be  sufficient  to 
save  the  animal  from  death,  even  after  it  has  been 
injected  with  ten  fatal  doses  of  the  diphtheria  toxin! 
Sometimes,  in  fact,  as  little  as  -g-^Vu-  cm.  suffices.  The 
strength  of  the  antitoxic  serum  is,  therefore,  expressed 
in  units.  In  the  examples  just  cited  the  serum  would 
be  said  to  have  a  strength  of  100  or  of  500  units 
respectively. 

Bacteriolysins. — Just  as  when  an  animal  injected 
with  gradually  increasing  doses  of  toxin  produces  an 
antitoxin  in  its  blood,  so  also,  when  injected  with  bac- 
teria, it  produces  substances  which  kill  and  dissolve 


68  APPLIED    BACTERIOLOGY   FOR   NURSES 

the  injected  micro-organisms.  We  have  already  said 
that  fresh  blood-serum  is  able  to  kill  a  considerable  num- 
ber of  bacteria;  when  injected  with  gradually  increas- 
ing amounts  of  bacteria,  however,  this  destructive  power 
increases  enormously,  but  only  for  the  particular  kind  of 
bacterium  used  for  injection.  Thus,  if  an  animal  is 
injected  with  typhoid  bacilli  the  serum  will,  after  a  time, 
kill  enormous  numbers  of  typhoid  bacilli,  even  in  very 
small  doses;  tested  against  cholera  bacilli,  or  any  other 
bacteria,  its  destructive  effect  is  merely  that  of  normal 
serum  from  an  untreated  animal.  When  the  action  of 
the  serum  on  the  bacteria  is  studied  under  the  micro- 
scope it  is  seen  that  the  bacteria  are  actually  dissolved. 
Hence,  such  a  serum  is  spoken  of  as  a  "bacteriolysin," 
which  means  bacteria  dissolving.  Since  the  bacteria 
are  killed  by  this  action,  we  also  speak  of  the  serum  as 
being  "bactericidal,"  which  means  bacteria  killing. 

It  has  been  found  that  this  action  of  the  serum  may 
be  developed  against  other  cells  than  bacteria.  When 
red  blood-cells  are  used  the  serum  acquires  dissolving 
properties  for  these;  and  here,  again,  the  action  is 
strictly  specific,  so  that  when  blood-cells  from  a  chicken 
are  injected  into  an  animal  the  serum  of  the  injected 
animal  acquires  increased  solvent  powers  only  for 
chicken  blood-cells,  but  not  for  blood-cells  of  other 
animals.  Instead  of  using  the  word  bacteriolysin,  we 
speak  of  such  a  serum  as  a  hemolysin,  meaning  blood 
dissolving. 

The  term  "  cytolysin  "  is  used  to  embrace  all  these 
dissolving  sera,  "cyto"  signifying  cell;  hence,  cell 
dissolving. 

Investigation  showed  that  the  mode  of  action  of  these 


IMMUNITY  69 

dissolving  sera  was  somewhat  complex  and  required  the 
joint  action  of  two  different  constituents.  One  of  these 
constituents  decomposes  very  easily,  so  that  a  serum 
which  has  stood  several  days  may  be  found  to  have 
almost  entirely  lost  its  solvent  power.  Curiously,  how- 
ever, the  addition  of  a  little  fresh  serum,  even  from  a 
normal  animal,  immediately  restores  its  power.  This 
very  unstable  constituent,  which  is  present  in  all  serum, 
even  in  serum  from  normal  animals,  is  spoken  of  as 
complement,  because  it  completes  or  complements  the 
action  of  the  other  constituent.  The  stable  constituent 
is  called  the  amboceptor  or  the  immune  body. 

When  the  animal  is  repeatedly  injected  with  gradually 
increasing  doses  of  bacteria  (or  other  cells),  it  responds  by 
manufacturing  large  quantities  of  this  amboceptor  or 
immune  body,  directed  specifically  against  the  injected 
bacte'ria.  This  substance  lays  hold  of  the  invading  bac- 
teria, and,  with  the  aid  of  the  complement,  effects  their 
destruction.  The  complement  alone  would  be  unable  to 
destroy  the  bacteria;  the  amboceptor  is  needed  to  pre- 
pare the  bacteria  in  some  way  as  yet  unknown. 

Agglutinins. — When  the  serum  of  an  animal  which 
has  been  repeatedly  injected  with  gradually  increasing 
doses  of  bacteria  is  brought  into  contact  with  some  of 
these  bacteria,  careful  observation  under  a  microscope 
reveals  a  very  interesting  series  of  changes.  Thus,  if 
typhoid  bacilli  are  mixed  with  a  specific  antityphoid 
serum  (obtained,  say,  from  a  rabbit  previously  injected 
with  typhoid  bacilli),  one  notices  first  that  the  motility  of 
the  bacilli  becomes  markedly  diminished.  This  is  fol- 
lowed by  the  gradual  collection  of  the  bacilli  into  clumps. 
At  the  end  of  an  hour  or  two,  in  place  of  countless  bac- 


70  APPLIED    BACTERIOLOGY  FOR   NURSES 

teria  moving  quickly  through  the  field,  one  sees  merely 
several  groups  of  absolutely  immobile  bacilli.  If  the 
reaction  is  feeble,  the  clumps  are  small,  and  one  finds 
comparatively  many  isolated  and  perhaps  also  moving 
bacteria.  This  phenomenon  is  spoken  of  as  agglutina- 
tion, and  the  substance  in  the  serum  which  brings  it 
about  as  agglutinin.  The  clumping  thus  brought  about 
does  not  kill  the  bacteria;  moreover,  it  makes  no  differ- 
ence whether  the  serum  is  freshly  drawn  or  has  been 
kept  for  some  time,  it  will  agglutinate  equally  well,  and 
does  not  require  the  addition  of  fresh  serum  as  do  the 
bacteriolysins. 

Like  the  antitoxins  and  the  bacteriolysin,  the  ag- 
glutinins  are  strictly  specific,  i.  e.,  a  serum  from  an 
animal  injected  previously  with  typhoid  bacilli  will 
agglutinate  only  typhoid  bacilli;  one  from  an  animal 
injected  with  cholera  bacilli  will  agglutinate  only  cholera 
bacilli,  etc. 

Since  the  agglutinins  do  not  kill  the  bacteria,  it  may 
be  asked  what  their  function  is.  Up  to  the  present  time 
we  do  not  know.  Through  the  studies  of  Gruber  and  of 
Widal,  however,  the  agglutinins  have  come  to  play  a 
prominent  part  in  the  diagnosis  of  bacterial  infections, 
and,  in  what  is  called  the  Widal  reaction,  afford  an  im- 
portant aid  in  diagnosing  typhoid  fever.  The  Widal  test 
in  typhoid  fever  may  be  performed  with  blood-serum 
from  the  patient  or,  still  simpler,  with  a  drop  of  blood 
collected  on  a  glass  slide  and  allowed  to  dry.  If  the 
latter  method  is  employed,  the  drop  is  soaked  off  with 
sufficient  distilled  water  to  make  approximately  a  dilu- 
tion containing  1  part  of  blood  in  20  of  the  mixture. 
Next,  a  loopful  of  this  mixture  is  mixed  with  a  loopful 


IMMUNITY 


71 


of  a  broth  culture  of  typhoid  bacilli,  and  this  mixture 
of  diluted  blood  and  typhoid  culture  then  examined  by 


Fig.  23. — Typhoid  bacilli  unagglutinated  (Jordan). 

means  of  the  hanging-drop  method  under  the  micro- 
scope.    If  complete  agglutination  takes  place  within 


Fig.  24. — Typhoid  bacilli  partially  agglutinated  (Jordan). 

twenty  to  thirty  minutes,  one  speaks  of  having  obtained 
a  positive  Widal  reaction.    This  means  that  the  patient 


72  APPLIED   BACTERIOLOGY   FOR   NURSES 

is  suffering  from  typhoid  fever  or  has  recently  had  the 
disease,  for  the  serum  continues  to  show  the  reaction  for 
some  time  after  convalescence. 

Agglutination  reactions  may  also  be  employed  in  a 
reverse  manner  for  identifying  bacteria.  In  that  case, 
one  employs  an  agglutinating  serum  made  against  a 
certain  bacterium  and  tests  the  bacterium  one  is  study- 
ing. If  it  agglutinates  with  this  serum,  one  argues  that 
it  is  identical  with,  or  at  least  very  closely  related  to, 
the  bacterium  used  for  making  the  serum. 


Fig.  25. — Typhoid    bacilli,  showing    typic    clumping   by  typhoid 
serum  (Jordan). 

Opsonins. — We  have  already  said  that  the  white 
blood-corpuscles — i.  e.}  the  leukocytes — take  up  bac- 
teria and  destroy  them.  Sir  Almroth  Wright,  a  dis- 
tinguished English  physician,  discovered  that  certain 
substances  present  in  blood-serum  had  the  power  of  in- 
creasing the  appetite,  as  it  were,  of  the  leukocytes,  and, 
furthermore,  that  the  amount  of  these  substances 
could  be  increased  by  properly  administered  injections 
of  the  appropriate  bacteria.  These  substances  he  called 


IMMUNITY  73 

opsonins.  They  are  specific,  just  as  are  the  antitoxins, 
the  bacteriolysins,  and  the  agglutinins;  that  is  to  say, 
when  the  body  is  injected  with  typhoid  bacilli,  only 
the  opsonic  power  for  typhoid  bacilli  is  affected;  when 
staphylococcus  pyogenes  is  employed,  only  the  opsonic 
power  for  this  germ  is  affected;  when  pneumococci 
are  injected,  only  the  opsonic  power  for  pneumococci 
is  affected.  Wright  devised  a  special  techni-c  for  measur- 
ing the  amount  of  opsonin  present  in  a  serum,  and  ex- 
pressed this  in  what  he  calls  the  opsonic  index.  This 
is  merely  the  opsonic  power  of  the  patient's  serum,  as 
compared  with  the  opsonic  power  of  several  known  nor- 
mal sera,  using  the  same  leukocytes  and  the  same  bac- 
teria in  the  one  test.  Although  Wright  believes  that 
this  opsonic  index  is  essential  in  the  bacterial  vaccine 
treatment  of  infections,  most  other  observers  have 
failed  to  find  the  index  of  any  real  help. 

Precipitins  and  Other  Antibodies. — We  have  seen 
above  that  the  injection  into  the  animal  body  of  bac- 
teria or  other  cells  is  followed  by  the  production  of 
a  number  of  different  antibodies.  If,  instead  of  inject- 
ing bacteria,  we  inject  solutions  of  albuminous  material, 
for  example,  inject  a  rabbit  with  chicken  egg-albumin 
(white  of  egg),  we  shall  find  that  the  rabbit's  serum 
acquires  the  power  to  produce  a  precipitate  when  mixed 
with  chicken  egg-albumin.  This  action  is  highly  specific, 
so  that  if  the  serum  is  tested  against  albumin  from  any 
other  animal — e.  g.,  from  a  duck — no  precipitate  will  be 
produced.  If  a  rabbit  is  injected  with  human  blood 
(which,  of  course,  is  really  an  albuminous  solution)  the 
rabbit  serum  will  produce  a  precipitate  when  mixed  with 
human  blood,  but  not  when  mixed  with  any  other  blood. 


74  APPLIED    BACTERIOLOGY   FOR   NURSES 

The  antibodies  concerned  in  this  reaction  are  called 
precipitins.  The  precipitin  test  is  now  made  use  of  in 
criminal  cases  where  it  is  necessary  to  determine 
whether  certain  blood-stains  are  from  human  blood  or 
otherwise.  This  reaction  may  also  be  used  to  determine 
whether  sausage  contains  any  horse  meat.  In  addition 
to  the  foregoing,  still  other  antibodies  are  known. 
When  ferments  are  injected  into  an  animal,  the  latter 
responds  by  producing  antiferments.  When  certain 
antibodies  are  injected,  anti-antibodies  are  produced. 
The  entire  subject  is  extremely  complex,  and  further 
discussion  in  such  a  work  as  this  is  out  of  place. 

Anaphylaxis. — When  albuminous  substances  are  taken 
into  the  body  through  the  mouth,  that  is,  into  the  stom- 
ach and  intestines,  they  are  acted  on  by  certain  ferments, 
digested,  and  serve  as  body  nourishment.  When,  how- 
ever, they  are  introduced  through  other  channels — e.  g., 
by  means  of  hypodermic,  intramuscular,  or  intra- 
venous injection — they  cause  the  production  of  anti- 
bodies as  was  described  above.  Some  of  these  antibodies 
appear  to  have  digesting  properties;  at  least  they  split 
up  the  injected  material,  evidently  so  that  the  body 
may  get  rid  of  it.  Recent  studies  have  shown  that  this 
non-intestinal  splitting  up  of  albuminous  substances 
may  give  rise  to  serious  symptoms,  and  that  the  rashes 
sometimes  following  the  injection  of  diphtheria  anti- 
toxin are  due  to  this  cause.  It  has  been  found  that  such 
rashes  are  more  likely  to  follow  second  injections.  In 
experimenting  with  guinea-pigs  it  is  possible  to  so 
arrange  matters  that  the  second  injection  will  prove 
fatal.  This  phenomenon  is  spoken  of  as  anaphylaxis. 


IMMUNITY  75 

SERUM  AND  VACCINE  THERAPY 

The  principles  underlying  the  production  of  diphtheria 
antitoxin  have  already  been  described.  Injected  into  a 
patient  suffering  from  diphtheria,  the  antitoxin  at  once 
lays  hold  of  the  toxin  which  the  diphtheria  bacilli  are 
producing  and  quickly  restores  the  patient  to  health. 
The  great  convenience  in  the  use  of  diphtheria  antitoxin 
lies  in  the  fact  that  we  can  get  a  horse  to  produce  it  for 
us,  and  then  by  bleeding  the  animal,  collecting  the  se- 
rum, and  injecting  this  serum  into  man,  can  confer  im- 
munity against  diphtheria  on  the  person  so  injected.  We 
speak  of  this  kind  of  immunity  as  passive  immunity, 
because  the  man's  body  has  taken  no  active  part  in  the 
production  of  the  protective  substance,  the  antitoxin. 
It  is,  of  course,  plain  that  the  antitoxin  can  merely  ward 
off  from  the  cells  of  the  body  the  toxin  which  is  threaten- 
ing them;  the  toxin  which  has  already  begun  to  act  on 
the  cells  cannot  be  neutralized  by  the  antitoxin.  In 
every  case  of  diphtheria,  therefore,  it  is  most  important 
to  give  the  full  dose  of  antitoxin  as  early  as  possible,  and 
to  give  a  small  dose  also  to  all  who  have  been  or  expect 
to  be  in  direct  contact  with  the  patient. 

In  the  case  of  tetanus  antitoxin  the  clinical  results 
have  not  been  as  striking  as  with  diphtheria  antitoxin. 
Its  use  in  the  form  of  preventive  injections  has  undoubtedly 
saved  many  lives.  Moreover,  if  injected  intraspinally, 
tetanus  antitoxin  is  very  useful  in  the  treatment  of  tetanus. 
In  the  past,  when  the  serum  was  administered  intra- 
venously, the  therapeutic  results  were  very  poor.  One 
reason  why  the  serum  often  fails  in  the  treatment  of 
developed  cases  of  tetanus  is  because  the  diagnosis 


76  APPLIED    BACTERIOLOGY   FOR   NURSES 

cannot  possibly  be  made  until  after  the  toxin  has  had 
abundant  time  to  combine  with  the  body  cells.  In  the 
treatment  of  epidemic  cerebrospinal-  meningitis  spinal 
injections  of  specific  antimeningococcus  serum  have 
reduced  the  mortality  to  about  one-half  that  of  cases  not 
so  treated. 

So  far  as  the  bacteriolysins  are  concerned  the  clinical 
results  have  not  been  very  satisfactory.  Investigation 
has  disclosed  many  difficulties  which  must  still  be  over- 
come. In  speaking  of  these  sera  it  is  better  to  use  the 
term  "antibacterial,"  because,  after  all,  when  we  im- 
munize an  animal  against  a  certain  bacterium  we  do  not 
produce  merely  a  bacteriolysin,  but  a  serum  which 
contains  also  agglutinins,  precipitins,  opsonins,  and, 
perhaps,  still  other  antibodies. 

Because  of  the  non-success  attending  the  use  of  the 
antibacterial  sera,  attention  has  been  turned  to  treatment 
of  bacterial  infections  bv  means  of  active  immunization. 
Thus,  when  we  inject  a  horse  with  diphtheria  toxin  in 
order  to  produce  antitoxin  we  actively  immunize;  when  we 
inject  the  antitoxin  into  a  child  in  order  to  protect  the 
child  against  diphtheria  we  passively  immunize.  (See 
page  97.) 

Active  immunization  consists  usually  in  injecting  the 
patient  with  small  doses  of  dead  bacteria,  thus  causing  the 
production  on  his  part  of  the  various  antibodies  already 
described,  and  thus  bringing  about  a  condition  of  im- 
munity. The  bacteria  are  usually  grown  on  agar,  in  the 
ordinary  way,  and,  after  being  washed  off  into  a  test-tube 
containing  a  little  salt  solution,  are  heated  for  about 
half  an  hour  to  60°  C.  in  order  to  kill  all  the  bacteria. 
Sterility  is  insured  by  suitable  tests.  The  suspension  is 


IMMUNITY  77 

then  diluted  so  that  each  cubic  centimeter  will  contain 
exactly  a  certain  number  of  million  bacteria,  after  which 
it  is  ready  for  injection.  Such  a  suspension  is  spoken  of 
as  a  "bacterial  vaccine."  The  doses  of  the  different 
vaccines  vary.  In  the  case  of  staphylococcus  vaccine 
the  ordinary  dose  is  from  250,000,000  to  500,000,000. 
Gonococci  are  usually  given  in  much  smaller  doses, 
namely,  from  15,000,000  to  50,000,000.  The  dose  of 
typhoid  vaccine  is  from  500,000,000  to  1,000,000,000. 
The  vaccines  are  usually  given  in  several  doses,  injections 
being  made  from  five  days  to  a  week  apart. 

At  the  present  time  treatment  either  by  specific  sera 
or  by  bacterial  or  other  vaccines  is  employed  in — 

Diphtheria. — Antitoxic  serum  therapeutically.  Serum 
or  toxin  injections  for  immunization. 

Tetanus. — Antitoxic  serum,  both  therapeutically  and 
for  immunization. 

Epidemic  Cerebrospinal  Meningitis. — Specific  serum 
therapeutically.  Vaccines  have  been  used  for  immuniza- 
tion. 

Typhoid  Fever. — Vaccines  for  immunization.  Neither 
serum  nor  vaccines  of  use  therapeutically. 

Cholera. — Specific  serum  has  been  used  therapeutically; 
results  indifferent.  Vaccines  used  for  immunization. 

Plague. — Vaccines  have  been  tried  for  immunization. 

Tuberculosis. — Neither  therapeutically  nor  for  immuni- 
zation have  either  serum  or  vaccine  yielded  satisfactory 
results. 

Pneumonia. — Serum  therapeutically  has  apparently 
been  of  value  in  certain  types  of  cases.  Vaccines  have  not 
yielded  satisfactory  results. 


78  APPLIED   BACTERIOLOGY  FOR  NURSES 

Streptococcus  Infections. — Therapeutic  results  either 
with  serum  or  vaccines  have  been  unsatisfactory. 

Gonococcus  Infections. — Vaccines,  therapeutically,  use- 
ful in  certain  types  of  infection.  (See  page  116.) 

Boils  and  Other  Staphylococcus  Infections. — Vaccines, 
therapeutically,  have  been  of  value  in  certain  cases. 

Whooping-cough. — Vaccines  are  now  being  tried  thera- 
peutically. Results  somewhat  encouraging. 

Typhus  Fever. — A  vaccine  is  now  being  tried. 

Rabies. — Pasteur's  method  of  treatment  by  vaccines  is 
undoubtedly  of  great  value.  The  vaccine  consists  of  an 
emulsion  in  salt  solution  of  spinal  cord  from  a  rabbit  dead 
of  artificially  inoculated  rabies.  The  cord  is  dried  for  vary- 
ing periods  and  the  injections  are  made  daily,  beginning 
with  a  cord  dried  fourteen  days  and  changing  to  a  stronger 
cord  (dried  less),  so  that  finally  the  injected  material  con- 
sists of  a  cord  dried  only  three  days. 

Influenza. — Neither  serum  nor  vaccines  have  given  satis- 
factory results  either  therapeutically  or  for  immunization. 


SPECIAL   BACTERIOLOGY 


CHAPTER  XII 

TYPHOID  FEVER 

THE  typhoid  bacillus  was  discovered  in  1880  by 
Eberth.  It  is  a  motile  bacillus  about  ipoo  inch  long  and 
4o;ooo  inch  thick.  It  decolorizes  when  stained  according 
to  Gram's  method,  and  does  not  produce  spores.  Typhoid 
bacilli  grow  readily  on  the  ordinary  laboratory  media, 
even  at  room  temperature.  They  do  not  ferment  lac- 
tose (milk-sugar),  so  that  when*  grown  in  litmus  milk 
or  on  lactose  litmus  agar  they  do  not  change  the  color 
of  the  medium. 

Typhoid  fever  is  due  essentially  to  the  invasion  of  the 
body  by  typhoid  bacilli  which  lodge  in  certain  parts  of  the 
wall  of  the  small  intestine,  causing  ulceration  of  that  organ 
and  very  severe  constitutional  symptoms. 

A  curious  feature  of  the  disease  is  the  development, 
about  the  sixth  or  seventh  day  of  the  fever,  of  small  rose- 
colored  spots  on  the  patient's  trunk,  usually  on  the  abdo- 
men and  on  the  lower  part  of  the  back. 

In  typhoid  fever  the  bacilli  are  found  chiefly  in  certain 
parts  of  the  wall  of  the  small  intestine  aftdjn  the  intestinal 
contents.  In  early  stages  of  the  disease  tfrfcji  are  also 
found  in  the  blood,  and  they  are  also  present  in  the  rose 
spots  already  mentioned.  In  the  wall  of  the  intestine 

79 


80  APPLIED   BACTERIOLOGY   FOR   NURSES 

they  cause  ulceration,  and  this  frequently  involves  the 
blood-vessels,  giving  rise  to  severe  hemorrhages.  Some- 
times the  ulceration  passes  entirely  through  the  intes- 
tinal wall,  and  this  is  called  a  perforation.  With  the 
escape  of  fecal  matter  into  the  peritoneal  cavity  comes 
the  development  of  peritonitis.  In  many  cases  the 
typhoid  bacilli  are  found  not  only  in  the  feces  but  also 
in  the  urine.  This  is  important  to  remember  in  guarding 
against  infection  of  others. 

In  the  country,  where  privies  and  cesspools  are  com- 
mon, it  often  happens  that  typhoid  stools  insufficiently 
disinfected  find  their  way  into  a  well,  spring,  or  stream, 
and  so  lead  to  the  infection  of  others.  In  summer,  when 
flies  abound,  it  sometimes  happens  that  flies  carry 
infected  material  from  such  a  privy  directly  into 
the  kitchen,  and  deposit  typhoid  bacilli  on  the  food 
standing  about.  If  a  pitcher  of  milk  thus  becomes  in- 
fected, the  bacilli  at  once  thrive  and  multiply  so  that  in  a 
very  short  time  the  milk  contains  enormous  numbers 
of  typhoid  bacilli.  Some  infections  have  been  traced 
to  the  washing  of  dairy  utensils — cans,  etc. — in  typhoid- 
infected  water.  Other  cases  have  been  caused  by  un- 
recognized mild  cases,  especially  when  the  latter  had 
something  to  do  with  the  handling  of  food.  In  the 
city  a  large  number  of  cases  are  undoubtedly  due  to 
quite  direct  infection  from  a  previous  case.  It  is  now  well 
established  that  oysters  taken  from  beds  polluted  with 
sewage  may  carry  typhoid  infection.  This  is  more  apt 
to  happen  with  oysters  which  have  been  "fattened"  in 
sewage-polluted  water.  It  is  advisable,  therefore,  to  eat 
no  oysters  which  have  been  "fattened";  the  lean,  gray 
oyster  is  always  to  be  preferred.  When  a  patient  re- 


TYPHOID    FEVER  81 

covers  from  typhoid  fever  the  bacilli  usually  disap- 
pear from  the  feces,  but  in  about  5  per  cent,  of  the  cases 
the  patients  continue  to  harbor  bacilli  in  their  typhoid 
feces  although  they  themselves  are  perfectly  well.  Such 
persons  are  spoken  of  as  "bacillus  carriers,"  and  constitute 
a  very  difficult  feature  of  the  typhoid  problem.  The 
author  has  traced  a  number  of  epidemics  of  typhoid  fever 
to  dairymen  who  were  such  bacillus  carriers. 

From  what  has  been  said  it  follows  that  great  care 
must  be  taken  to  properly  disinfect  the  discharges, 
both  urine  and  feces,  of  all  persons  having  typhoid 
fever.  Moreover,  this  should  include  all  those  cases  of 
fever  in  which  the  presence  of  a  typhoid  infection  is  pos- 
sible, even  though  the  diagnosis  is  not  yet  positively 
established.  Many  a  case  of  obscure  fever,  running  a 
mild  course,  and  therefore  dismissed  as  of  no  conse- 
quence, has  subsequently  been  found  to  have  been 
typhoid  fever,  and  resulted  in  the  infection  of  others 
because  no  typhoid  precautions  were  taken.  Chlorid 
of  lime  is  one  of  the  most  efficient  disinfectants  for  the 
stools,  but,  like  all  disinfectants,  it  should  be  used 
freely,  and  in  such  a  way  that  the  disinfectant  will 
really  remain  in  contact  with  the  feces  for  a  sufficient 
time.  If  the  masses  of  feces  are  hard,  a  constipated 
stool,  it  is  important  to  break  them  up  with  a  stick  and 
mix  them  thoroughly  with  the  disinfectant.  Ordinarily 
it  is  well  to  keep  the  disinfectant  in  contact  with  the 
stool  in  the  vessel  for  about  an  hour  before  emptying 
the  vessel.  In  the  city  the  stool  can  then  be  poured 
into  the  closet;  in  the  country,  where  there  is  merely  a 
shallow  earth  closet,  it  is  advisable  to  bury  the  stools. 
The  underclothing,  night  clothes,  handkerchiefs,  towels, 


82  APPLIED    BACTERIOLOGY    FOR    NURSES 

etc.,  of  the  patient,  as  well  as  the  bed-linen,  must  be 
carefully  disinfected  before  it  is  given  out  to  be  laundered. 
Disinfection  of  these  articles  is  accomplished  by  soaking 
them  for  some  hours  in  carbolic  acid  solution  of  from 
2  to  5  per  cent.  Bichlorid  of  mercury  solution,  1 : 5000, 
can  also  be  similarly  used.  Very  useful  in  deodorizing 
and  disinfecting  stools  is  the  solution  of  chlorids  put  up 
by  many  druggists.  For  the  purposes  of  at  once  disin- 
fecting the  hands  after  handling  the  patient,  the  nurse 
should  have  standing  near  the  bed  a  basin  containing 
either  5  per  cent,  carbolic  acid  solution,  or  1 : 1000 
bichlorid  of  mercury,  or  some  other  convenient  hand 
disinfectant  of  similar  strength.  In  this  more  than  in 
any  other  infectious  disease  it  is  important  to  keep 
flies  out  of  the  sick  room. 

When  typhoid  bacilli  are  examined  under  the  micro- 
scope in  a  drop  of  sterile  water  they  will  be  found  to  be 
uniformly  scattered  throughout  the  drop  and  in  active 
motion.  When  to  such  a  drop  a  little  blood  from  a 
typhoid  patient  is  added  the  bacilli  at  once  begin  to 
gather  together  in  clumps  and  cease  their  movements. 
Blood  from  a  normal  person  has  no  such  effect.  This 
reaction  is  very  valuable  for  diagnosis,  and  is  known  as 
the  "Widal  test"  for  typhoid  fever.  It  has  been  found 
that  blood  from  a  typhoid  patient  can  be  diluted  from 
twenty  to  forty  times  or  more,  and  still  produce  this 
peculiar  clumping  effect;  in  some  cases,  in  fact,  diluting 
the  blood  several  thousand  times  still  permits  the 
reaction  to  take  place.  The  collection  of  the  blood  for 
the  test  is  a  very  simple  matter,  as  a  couple  of  drops  of 
blood  dried  on  a  glass  slide  suffice.  It  is  important, 
however,  to  let  the  blood  dry  spontaneously,  and  not 
attempt  to  hasten  the  drying  by  heat. 


TYPHOID   FEVER  83 

Thanks  largely  to  the  work  of  Wright,  much  has  been 
done  to  prevent  infection  with  typhoid  bacilli  by  pro- 
tecting the  individual  through  antityphoid  vaccination. 
For  this  purpose  a  bacterial  vaccine  is  used,  the  typhoid 
bacilli  being  very  carefully  killed  by  heat.  The  vaccina- 
tion should  consist  of  three  injections  a  week  apart. 
The  first  one  contains  500,000,000  bacilli,  and  the  second 
and  third  each  1,000,000,000.  The  results  of  such  pro- 
tective vaccinations  have  been  excellent;  very  few  cases  of 
typhoid  fever  develop  among  those  so  vaccinated,  and  the 
cases  that  do  occur  run  a  milder  course. 

Treatment  of  developed  cases  of  typhoid  fever  by  means 
of  these  vaccines  or  by  specific  sera  has  proved  to  be  with- 
out value. 


CHAPTER  XIII 
DYSENTERY— CHOLERA 

DYSENTERY 

THE  dysentery  bacillus  was  discovered  by  Shiga  in 
Japan,  and  by  Flexner  in  the  Philippines.  It  is  a 
Gram-negative,  non-motile  bacillus,  somewhat  smaller 
than  the  typhoid  bacillus.  Two  main  varieties  are  en- 
countered, those  which  ferment  mannite  (a  kind  of 
sugar)  and  those  which  do  not. 

Acute  dysentery,  in  this  climate,  is  usually  due  to  the 
dysentery  bacillus  or  some  closely  related  variety. 
In  tropical  countries  a  form  of  chronic  dysentery  is  due 
to  organisms  called  amebse,  and  it  is,  therefore,  customary 
to  speak  of  "bacillary  dysentery"  and  "amebic  dysen- 
tery." The  usual  summer  diarrheas,  however,  are  not 
due  to  dysentery  bacilli. 

Like  typhoid  fever,  bacillary  dysentery  is  due  to  the 
swallowing  of  bacilli  which  have  come  from  the  fecal 
discharges  of  another  person.  Sometimes  these  bacilli 
are  carried  quite  directly,  sometimes  indirectly,  on  food 
and  drink.  Occasionally  the  germs  are  carried  by  flies. 

Bacillary  dysentery  affects  especially  the  mucous 
membrane  of  the  large  intestine.  In  mild  cases  only  the 
superficial  portion  is  involved,  but  in  severe  cases  deep 
ulceration  may  occur.  The  stools  are  at  first  fecal,  but 
soon  become  nothing  but  mucus  and  serum.  The  mucus 

84 


DYSENTERY — CHOLERA 


85 


resembles  calf's  foot  jelly  in  appearance;  it  is  frequently 
bloody.  When  the  disease  is  at  its  height  there  are  from 
twenty  to  fifty  stools  in  the  twenty-four  hours.  At  this 
time  dysentery  bacilli  are  very  abundant  in  the  stools 
and  the  superficial  layers  of  the  affected  mucous  mem- 
brane. With  the  return  of  the  fecal  stools  the  bacilli 
disappear. 

The  path  of  infection  in  dysentery  is  the  same  as  it 
is  in  typhoid  fever,  i.  e.,  by  means  of  infected  water, 
milk,  or  other  food  contaminated  from  the  stools  of 
dysentery  patients.  The  means  of  guarding  against 
infection  are,  therefore,  the  same  as  in  typhoid  fever. 
All  the  stools  should  be  carefully  disinfected,  one  of  the 
best  disinfectants  for  this  purpose  being  chlorid  of 
lime.  Careful  attention  should  be  paid  to  soiled  cloth- 


Fig.  26. — Bacillus  of  dysentery  from  agar  culture.     Fuchsin  stain 
(Kolle  and  Wassermann). 

ing  and  bedding,  and,  when  rectal  irrigations  have  been 
employed,  the  irrigation-tube  should  be  disinfected  by 
boiling. 


86  APPLIED   BACTERIOLOGY   FOR   NURSES 


CHOLERA 

The  spirillum  of  cholera  was  discovered  by  Koch  in 
1884,  and  from  its  form  is  often  called  the  "comma 
bacillus."  It  grows  well  on  ordinary  culture-media, 
even  at  room  temperature,  and  when  grown  on  gelatin 
causes  liquefaction  of  the  medium.  The  cholera  spirillum 
can  multiply  in  water.  It  is  motile,  does  not  produce 


Fig.  27. — Spirillum  of  Asiatic  cholera,  from  a  bouillon  culture  three 
weeks  old,  showing  long  spirals;  X  1000  (Frankel  and  Pfeiffer). 

spores,   and   is   decolorized   when   stained   according  to 
Gram's  method. 

Cholera  is  constantly  present  in  India  and  other  parts 
of  Asia,  hence  the  name  "Asiatic  cholera."  From  time 
to  time  enormous  epidemics  of  the  disease  invade  Europe, 
causing  thousands  of  deaths. 


DYSENTERY — CHOLERA  87 

The  disease  is  produced  only  by  swallowing  the  germs 
of  cholera,  and  since  the  germs  invariably  come  only  from 
the  intestinal  contents  of  man,  it  follows  that  sewage  pollu- 
tion of  water,  the  contamination  of  milk  and  food  through 
handling  by  cholera  patients,  and  food  infection  through 
flies  constitute  the  common  avenues  of  infection. 

Unlike  the  typhoid  bacillus,  the  cholera  spirillum  does 
not  penetrate  deep  into  the  wall  of  the  intestine,  but 
produces  an  intense  poison  while  multiplying  in  the  intes- 
tinal contents  and  in  the  superficial  layers  of  the  intestinal 
mucous  membrane.  The  absorption  of  the  poison  pro- 
duces the  clinical  symptoms  of  the  disease.  These  begin 
with  diarrhea  and  colicky  pain  in  the  abdomen.  In  a 
short  time  the  diarrhea  becomes  intense  and  profuse 
and  is  accompanied  by  vomiting.  Many  of  the  pa- 
tients die  at  this  period  in  a  state  of  collapse.  The 
stools  are  at  first  yellowish,  but  soon  become  grayish 
white,  and  are  then  termed  "rice- water  stools."  These 
discharges  often  contain  the  cholera  spirilla  in  practically 
pure  culture.  When  recovery  takes  place  the  stools 
gradually  resume  their  normal  color  and  the  cholera 
spirilla  disappear. 

The  disease  is  spread  chiefly  by  contaminated  water 
used  for  drinking,  cooking,  and  washing.  Vegetables 
washed  in  infected  water,  particularly  lettuce,  cress, 
and  the  like,  may  convey  the  disease.  Wash- women 
and  others  who  are  brought  into  very  close  contact  with 
the  linen  of  cholera  patients  or  their  stools  are  prone  to 
contract  the  disease.  Like  in  typhoid  fever,  it  has 
recently  been  found  that  some  healthy  persons  may 
carry  cholera  germs  in  their  stools.  These  are  spoken 


88  APPLIED   BACTERIOLOGY   FOR   NURSES 

of  as  "bacilli  carriers,"  and  have  already  been  spoken  of 
in  connection  with  typhoid  fever. 

So  far  as  the  prevention  of  further  infection  is  con- 
cerned, the  same  precautions  must  be  taken  as  have 
already  been  described  under  Typhoid  Fever  and  under 
Dysentery. 


CHAPTER  XIV 

TUBERCULOSIS 

THE  bacillus  of  tuberculosis,  also  called  the  tubercle 
bacillus,  was  discovered  by  Koch  in  1882.  It  is  the  cause 
not  only  of  " consumption"  (tuberculosis  of  the  lungs), 
but  also  of  all  other  forms  of  tuberculosis,  such  as 
tuberculosis  of  bone  (Pott's  disease,  hip-disease,  white 
swelling,  cold  abscess),  tuberculosis  of  the  intestines; 
of  the  peritoneum,  of  the  kidney,  of  the  meninges,  of 
glands  (scrofula),  etc.  The  tubercle  bacillus  is  a  slender 
rod,  iojob  inch  long  and  75^0  inch  thick.  It  is  strictly 
aerobic,  grows  only  on  special  media,  and  then  but 
slowly,  is  not  motile,  and  does  not  produce  spores.  It 
stains  with  difficulty,  but,  once  stained,  resists  decolor- 
ization  with  acids.  It  is,  therefore,  spoken  of  as  an 
"acid-fast"  bacillus.  (See  Plate  I.) 

Tuberculosis  is  an  extremely  common  disease  in  man, 
and  causes  about  one-eighth  of  all  deaths.  The  disease 
is  also  very  prevalent  among  cows,  and  hence  tubercle 
bacilli  are  often  found  in  cows'  milk.  The  tubercle 
bacilli  from  this  source  differ  somewhat  from  those 
found  in  human  pulmonary  tuberculosis,  and  until 
recently  there  was  considerable  controversy  regarding 
the  role  of  bovine  tuberculosis  in  the  spread  of  tuber- 
culosis in  man.  It  is  now  established  that  while  pul- 
monary tuberculosis  is  practically  always  caused  by 
bacilli  of  human  origin,  certain  other  tuberculous  in- 

89 


90  APPLIED   BACTERIOLOGY  FOR  NURSES 

factions,  especially  in  children,  are  due  to  milk  from 
infected  cows,  and  that  the  danger  should  be  guarded 
against. 

In  man  the  most  common  form  of  tuberculous  infec- 
tion is  that  of  the  lung.  In  this  situation  the  bacilli 
set  up  destructive  inflammatory  changes,  and  as  a 
result  of  these  a  considerable  quantity  of  sputum  is 
usually  coughed  up.  This  sputum  is  loaded  with  tubercle 
bacilli,  and  is,  therefore,  highly  infectious.  During  the 
act  of  coughing  and  sneezing  tiny  particles  of  infected 
sputum  are  scattered  into  the  air  and  may  be  inhaled  by 
other  persons  in  the  vicinity.  Or  these  infected  particles 
may  lodge  on  the  furniture,  hangings,  floor,  etc.,  in  the 
form  of  dust,  and  so  again  constitute  a  grave  menace  to 
others.  In  tuberculosis  of  the  intestine  (tuberculous 
enteritis)  tubercle  bacilli  are  found  in  large  quantities 
in  the  feces,  and  this  source  of  infection  must  be  guarded 
against.  For  that  matter,  even  in  ordinary  pulmonary 
tuberculosis  tubercle  bacilli  are  usually  found  in  the 
feces,  owing  to  the  fact  that  the  patients  swallow  some 
of  their  sputum. 

There  is  hardly  an  organ  which  may  not  be  attacked  by 
the  tubercle  bacillus.  Tuberculosis  of  the  spine,  or  Pott's 
disease,  is  the  common  cause  of  hunch-back;  tuberculosis 
of  the  meninges  (tuberculous  meningitis)  is  familiar  to  us 
as  hydrocephalus  or  water-on-the-brain,  met  with  in  in- 
fancy; tuberculosis  of  the  hip-joint  is  usually  called,  for 
short,  "hip  disease."  Other  common  forms  of  tuberculous 
infection  are  tuberculous  peritonitis,  tuberculous  pleurisy, 
tuberculosis  of  the  kidney,  tuberculosis  of  the  bladder, 
tuberculosis  of  the  larynx,  tuberculosis  of  the  skin,  tuber- 
culosis of  the  eye,  tuberculosis  of  bone,  gland  tuberculosis, 
etc. 


PLATE  I 


Bacillus  tuberculosis  in  sputum,  stained  with  carbolic  fuchsin  and 
aqueous  methylene-blue.     X  1000  (Ohlmacher). 


TUBERCULOSIS  91 

As  already  said,  however,  tuberculosis  of  the  lung  is  by 
far  the  most  frequent  form  of  infection.  In  seeking 
to  prevent  the  infection  of  others,  therefore,  it  is  im- 
portant that  the  consumptive  be  carefully  instructed  to 
always  spit  into  a  vessel  containing  some  disinfectant,  or 
into  a  paper  sputum  cup  which  can  be  burned  each 
day.  In  coughing,  the  scattering  about  of  droplets 
of  sputum  should  be  prevented  by  holding  a  paper 
handkerchief  in  front  of  the  mouth.  The  consump- 
tive's room  should  contain  no  unnecessary  furniture, 
bric-a-brac,  hangings,  or  other  objects  likely  to  catch 
dust.  Remembering  that  drying  and  sunlight  are 
potent  in  the  destruction  of  bacteria,  it  follows  that 
the  maximum  of  air  and  sunshine  should  be  provided. 
Dry  sweeping  should  not  be  permitted,  dust  should  al- 
ways be  wiped  up  with  a  rag  dampened  with  crude  oil. 
From  what  has  been  said  concerning  the  bacteriology  of 
tuberculosis,  other  precautions  will  suggest  themselves. 

When  tubercle  bacilli  are  grown  for  a  time  in  glycerin 
beef-broth,  they  gradually  cause  the  broth  to  become 
loaded  with  poisons.  When  such  a  broth  culture  is 
evaporated  and  filtered,  so  as  to  be  entirely  free  from 
tubercle  bacilli,  we  have  what  is  known  as  tuberculin. 
A  curious  thing  about  this  tuberculin  is  that  when 
minute  quantities  are  injected  into  an  individual  in- 
fected with  tuberculosis,  a  characteristic  reaction  takes 
place,  marked  by  fever,  prostration,  some  pains,  in- 
creased cough,  etc.  In  a  normal,  uninfected  'individual 
no  such  reaction  is  produced.  This  tuberculin  reaction 
is  thus  of  diagnostic  value.  It  can  also  be  applied  by 
scarifying  the  skin  with  a  needle  and  rubbing  a  drop  of 
tuberculin  into  the  scarifications.  A  positive  reaction 


92  APPLIED   BACTERIOLOGY   FOR   NURSES 

is  denoted  by  distinct  inflammatory  changes  at  the  site 
of  the  inoculation.  This  method  of  making  the  test  is 
often  spoken  of  as  the  von  Pirquet  test.  If  a  dilute 
solution  of  tuberculin  is  dropped  into  the  eyes,  it  may 
give  rise  to  a  reaction  in  the  form  of  a  marked  conges- 
tion of  the  conjunctiva.  This  is  spoken  of  as  the  con- 
junctival  or  Calmette  reaction.  Rubbed  into  the  skin 
in  the  form  of  an  ointment,  tuberculin  may  also  give  rise 
to  a  reaction.  This  is  Moro's  test. 

Tuberculin  is  also  used  in  the  treatment  of  tubercu- 
losis. For  this  purpose  very  minute  quantities  are  in- 
jected and  the  amounts  gradually  increased. 


CHAPTER  XV 

DIPHTHERIA 

THE  diphtheria  bacillus  was  discovered  by  Klebs,  and 
first  isolated  in  pure  culture  by  Loffler.  It  is,  therefore, 
usually  spoken  of  as  the  Klebs-Loffler  bacillus.  It 
is  rather  long  and  thin,  frequently  somewhat  clubbed 
at  the  ends,  and  possesses  peculiar  staining  properties. 
It  is  a  non-motile,  Gram-positive,  strictly  aerobic 


Fig.  28. — Bacillus  of  diphtheria,  fifteen-hour  serum  culture.    Loffler's 
methylene-blue;  X  2000  (Denny,  Journal  of  Medical  Research). 

organism,  and  produces  a  powerful  poison,  diphtheria 
toxin,  when  grown  in  broth  cultures. 

The  regions  most  frequently  invaded  by  the  diph- 
theria bacillus  are  the  tonsils  and  palate,  the  nasal 
passages,  and  the  larynx.  The  characteristic  feature  of 
the  inflammation  produced  by  this  bacillus  is  the  forma- 


94  APPLIED    BACTERIOLOGY    FOR   NURSES 

tion  of  a  peculiar  dirty  gray  membrane  on  the  surface  of 
the  part.  This  membrane  consists  of  fibrin,  pus  cells, 
and  granular  debris,  and  contains  numerous  diphtheria 
bacilli.  Somewhat  similar  membranes,  however,  are 
produced  by  other  bacteria,  especially  by  streptococci, 
and,  while  an  experienced  clinician  can  often  tell  by 
the  appearance  of  the  membrane  whether  the  infection  is 
due  to  the  diphtheria  bacillus  or  not,  most  physicians 
prefer  to  have  the  diagnosis  established  by  bacteriologic 
examination.  This  should  be  done  by  spreading  some 
of  the  membrane  on  a  slide,  fixing,  and  staining  with 
Loffler's  alkaline  methylene-blue,  and  then  examining 
under  the  microscope.  In  addition,  where  the  facilities 
are  at  hand,  by  means  of  a  sterile  swab  rubbed  first 
over  the  membrane,  and  then  over  the  surfac'e  of  a  tube 
of  sterile  Loffler's  serum,  a  culture  is  made,  incubated  for 
from  twelve  to  eighteen  hours,  and  the  growth  ex- 
amined under  the  microscope.  In  cases  of  true  diph- 
theria such  a  culture  will  usually  show  enormous  num- 
bers of  diphtheria  bacilli.  Both  methods  should  be 
employed  in  order  to  insure  a  correct  diagnosis,  for  cer- 
tain germs,  for  example,  those  of  Vincent's  angina,  will 
not  grow  on  the  culture-medium. 

Knowing  the  location  of  the  diphtheria  bacilli,  it  is 
not  difficult  to  devise  measures  to  prevent  the  infection 
of  others.  All  the  mouth  and  nasal  discharges  must  be 
carefully  disinfected,  carbolic  acid  being  very  useful  for 
this  purpose.  Disinfection  should,  of  course,  extend  to 
spoons,  glasses,  and  other  things  coming  in  contact 
with  the  mouth.  When  examining  the  throat  it  is  well 
to  interpose  a  pane  of  glass  between  the  patient  and  ex- 
aminer, in  order  to  safeguard  the  latter  when  the  patient 


DIPHTHERIA 


95 


coughs.    Quarantine  is  usually  kept  up  until  bacteriologic 
examination  shows  the  absence  of  diphtheria  bacilli. 

In  1893  Behring,  a  German  scientist,  found  that 
animals  could  be  accustomed  to  injections  of  diphtheria 
poison,  and  that  after  a  time  the  blood  of  these  animals 
had  acquired  the  power  to  cure  other  animals  injected 
with  many  times  a  fatal  dose  of  diphtheria  poison. 


Fig.  29. — 1,  A  tube  of  blood-serum;  2,  a  sterilized  cotton  swab  in 
test-tube.  Rub  the  swab  gently  but  freely  against  the  visible  exu- 
date,  and  without  laying  it  down,  after  withdrawing  the  cotton  plug 
from  the  culture-tube,  insert  it  into  the  latter,  and  rub  that  portion 
which  has  touched  the  exudate  gently  but  thoroughly  over  the  sur- 
face of  the  blood-serum  without  breaking  its  surface.  Now  replace 
the  swab  in  its  own  tube,  plug  both  tubes,  and  place  them  in  the 
box  provided  by  the  health  officials.  This  is  to  be  sent  to  the  bac- 
teriologic expert.  In  laryngeal  diphtheria  the  swab  is  to  be  passed 
far  back  and  rubbed  freely  against  the  mucous  membrane  of  the 
pharynx  and  tonsils  (Anders). 


We  have  already  said  that  the  diphtheria  bacillus  when 
grown  in  broth  produces  a  strong  poison.  In  fact,  the 
diphtheria  bacilli  produce  all  their  evil  effects  through  this 
poison.  The  bacilli  remain  on  the  surface,  i.  e.,  they  do 
not  enter  the  blood,  nor  do  they  invade  the  deeper  tissues. 
In  this  respect  they  differ  from  streptococci,  which,  as 
already  stated,  may  also  give  rise  to  a  membranous  in- 
flammation of  the  throat.  The  streptococci  penetrate  the 


96 


APPLIED   BACTERIOLOGY    FOR   NURSES 


tissues,  enter  the  blood-stream,  and  often  lead  to  inflam- 
mation in  other  parts  of  the  body,  arthritis,  endocarditis, 
pyemia,  etc. 


Fig.  30. — Injecting  horse  with  toxin.     (Courtesy  of  H.  K.  Mulford 
Company,  Phila.) 

The  poison  produced  by  diphtheria  bacilli  is  spoken 
of   as   diphtheria   toxin.     The   something   in   the   blood 


Fig.  31. — Bleeding  horse  in  operating-room.  Every  precaution 
is  taken  to  insure  asepsis.  (Courtesy  of  H.  K.  Mulford  Company, 
Phila.) 

of  the  treated  animals  which  was  able  to  overcome  or 
neutralize  the  effects  of  the  diphtheria  toxin  is,  there- 


DIPHTHERIA  97 

fore,  called  diphtheria  antitoxin.  At  the  present  time 
this  diphtheria  antitoxin  is  made  by  injecting  horses 
with  gradually  increasing  doses  of  diphtheria  toxin  over 
a  period  of  several  months,  until  at  last  the  horse  will 
stand,  at  one  injection,  as  much  diphtheria  toxin  as 
would  ordinarily  suffice  to  kill  several  hundred  horses. 
Then  the  animal  is  bled,  as  much  as  ten  quarts  of  blood 
being  sometimes  collected  at  one  bleeding.  When  this 
blood  is  allowed  to  stand  in  a  sterile  vessel,  in  a  cool 
place,  it  clots,  and  a  clear,  light-yellow  fluid  separates. 
This  fluid  is  the  blood-serum,  and  constitutes  the 
diphtheria  antitoxic  serum  used  in  the  treatment  of 
the  disease.  It  is  necessary  to  carefully  test  this  anti- 
toxic serum  for  purity  and  also  for  its  strength.  The 
latter  is  indicated  by  finding  out  against  how  many 
fatal  doses  of  toxin  a  certain  quantity  of  the  serum  will 
protect  an  animal.  This  is  expressed  by  saying  the 
serum  contains  so  many  units  per  cubic  centimeter.1 
The  ordinary  sera  now  on  the  market  contain  from  500 
to  1500  units  per  cubic  centimeter. 

In  the  treatment  of  diphtheria  the  antitoxic  serum 
should  be  given  early  and  in  full  doses  (from  3000  to 
10,000  units,  depending  on  the  severity  of  the  disease). 
Ordinarily  the  serum  is  given  by  means  of  hypodermic 
injections,  but  in  severe  cases,  especially  when  seen  late, 
it  is  well  to  make  the  injections  directly  into  a  vein. 
When  there  are  several  children  in  the  family  affected, 
injections  may  also  be  given  to  the  well  children,  in 
order  to  prevent  their  contracting  the  disease.  Such 

1  As  a  matter  of  fact,  one  unit  is  that  amount  of  antitoxin  which 
will  just  protect  a  guinea-pig  against  100  fatal  doses  of  diphtheria 
toxin. 

7 


98  APPLIED   BACTERIOLOGY   FOR   NURSES 

injections  are  spoken  of  as  "immunizing  injections"; 
the  dose  for  this  purpose  is  usually  1000  units. 

Schick  Reaction. — A  few  years  ago  Schick,  of  Vienna, 
devised  a  simple  skin  reaction  by  which  to  determine 
whether  or  not  an  individual  was  susceptible  to  diphtheria 
infection.  The  test  consists  in  the  injection  into  the  skin 
of  a  small  amount  of  diphtheria  toxin.  Within  twenty- 
four  to  forty-eight  hours  a  marked  area  of  redness  and 
induration  develops  in  those  who  are  susceptible;  in  those 
not  susceptible  there  is  practically  no  reaction.  The 
Schick  test  is  being  used  extensively  to  determine  the  need 
of  immunizing  children  exposed  to  diphtheria  infection. 

When  we  immunize  a  person  against  diphtheria  by 
means  of  diphtheria  antitoxin  the  immunity  conferred 
lasts  only  a  few  weeks.  This  is  because  the  antitoxin  in- 
jected is  horse  antitoxin  and  so  is  really  a  foreign  substance 
in  the  human  body.  For  this  reason  the  plan  has  recently 
been  adopted  of  making  a  person  immune  against  diph- 
theria by  injecting  him  with  diphtheria  bacilli  and  diph- 
theria toxin,  thus  causing  the  body  to  produce  its  own 
antitoxin.  This  plan,  spoken  of  as  active  immunization, 
has  been  extensively  tried  by  Park  and  Zingher,  and  ap- 
pears to  yield  excellent  results. 


CHAPTER  XVI 

TETANUS 

TETANUS  is  caused  by  a  bacillus  which  was  first  ob- 
tained in  pure  culture  by  Kitasato  in  1889,  five  years 
after  Nicolaier  .had  succeeded  in  producing  tetanus  in 
laboratory  animals  by  inoculating  them  with  garden 
earth.  In  spite  of  the  relatively  frequent  occurrence 
of  the  bacillus  of  tetanus  in  street  dust,  garden  earth, 
manure,  etc.,  tetanus  is  a  rather  rare  disease.  This  is 
due  to  the  fact  that  certain  conditions  must  be  present 
before  the  germ  can  do  its  deadly  work.  Thus,  inocula- 
tion with  a  pure  culture  rarely  produces  the  disease,  but 
if  other  bacteria  and  dirt  are  introduced  into  the  wound 
at  the  same  time  the  bacillus  can  elaborate  its  toxin. 
An  open  wound  is  not  nearly  so  favorable  for  its  de- 
velopment as  a  small  deep  puncture  or  laceration;  the 
type  of  wound  which  most  frequently  leads  to  tetanus  is 
that  made  by  a  Fourth-of-July  toy  pistol.  The  bacillus 
of  tetanus  does  not  grow  in  the  presence  of  oxygen, 
i.  e.,  it  is  an  anaerobe,  and  is  usually  cultivated  in  the 
laboratory  in  an  atmosphere  of  hydrogen  gas,  or  in  air 
from  which  oxygen  has  been  abstracted.  If  this  condi- 
tion is  fulfilled,  it  grows  quite  well  on  the  ordinary  cul- 
ture-media, producing  gas  and  a  very  disagreeable  odor. 

Grown  under  favorable  conditions,  the  bacillus  is  a 
slender  rod,  of  medium  length,  which  is  not  decolorized 
by  Gram's  stain,  i.  e.,  it  is  "Gram-positive."  It  is  able 
to  travel  across  the  microscopic  field,  owing  to  the  pres- 


100 


APPLIED   BACTERIOLOGY    FOR   NURSES 


ence  of  flagella,  which  are  arranged  around  its  entire 
body.  It  shows  greater  resistance  than  most  other 
bacteria  to  drying,  to  heat,  and  to  chemic  disinfectants, 
because  it  has  the  power  to  produce  spores  under  ad- 
verse conditions.  The  spore  is  located  at  one  end  of  the 
bacillus,  and,  being  larger  in  diameter  than  the  bacillus 
itself,  gives  to  the  latter  somewhat  the  appearance  of  a 
nail.  Heating  to  105°  C.  for  ten  minutes  is  sufficient  to 


Fig.  32. — Bacillus  of  tetanus,  showing  spores.     Pure  culture  on 
Fuchsin  stain  (Kolle  and  Wassermann). 


kill  tetanus  spores,  yet  they  have  remained  alive  on 
splinters  of  wood  and  have  caused  the  disease  after 
eleven  years. 

When  tetanus  bacilli  are  introduced  into  a  wound  they 
remain  there  and  do  not  invade  the  body  as  do,  for  ex- 
ample, the  streptococci.  It  is  important  to  bear  this  in 
mind.  If  the  conditions  are  favorable  they  continue 
to  live  and  multiply.  They  give  rise  to  but  little  local 
disturbance;  in  fact,  local  symptoms  are  frequently  absent. 
But  the  bacilli  produce  a  powerful  toxin  which  is  the 
cause  of  the  general  symptoms.  The  toxin  can  be  sepa- 


TETANUS 


101 


rated  from  cultures  by  filtration  through  a  Berkefeld  filter, 
and  causes  typical  tetanus  when  introduced  into  animals. 
Its  action  is  weakened  by  exposure  to  light  and  entirely 
destroyed  by  heating  to  55°  C.  and  over.  Like  diphtheria 
toxin,  tetanus  toxin,  when  injected  in  small  and  gradually 
increasing  doses  into  horses,  produces  in  the  serum  of 
these  animals  an  antitoxin.  In  fact,  the  toxin-antitoxin 
reactions,  which  have  become  so  important  in  diph- 
theria, were  first  studied  in  connection  with  the  bacillus 
of  tetanus.  The  serum  of  immunized  horses  protects 
laboratory  animals  against  experimental  tetanus,  and 
it  was  thought  that  the  same  might  be  used  in  the 
treatment  of  tetanus  in  -man.  But,  unfortunately, 
tetanus  symptoms  develop  late,  anywhere  from  four  to 
fourteen  days  after  inoculation,  while,  to  be  of  service, 
the  antitoxin  must  be  given  before  the  toxin  has  spread 
through  the  system.  To  obtain  the  best  results  the  anti- 
toxin should  be  injected  intraspinally.  Nicoll,  of  New 
York,  has  used  the  antitoxin  in  this  way  and  has  saved  a 
considerable  proportion  of  cases.  If  for  any  reason  spinal 
injections  cannot  be  given,  the  antitoxin  should  be  injected 
intravenously.  In  such  a  case  10,000  units  (U.  S.  stand- 
ardization) should  be  given  and  repeated  every  eight  to 
twelve  hours. 

(Tetanus  antitoxin  is  prepared  like  diphtheria  anti- 
toxin, but  its  standardization  is  not  uniform,  each 
country  having  its  own  standard  unit.)- 

In  New  York  City  during  the  last  few  years  appar- 
ently good  results  have  been  obtained  with  immuniz- 
ing doses;  1500  (U.  S.)  units  have  been  injected  in  cases 
where  any  suspicion  of  infection  existed,  mainly  in 
Fourth-of-July  wounds,  and  no  cases  of  tetanus  have 
developed  where  this  method  was  pursued. 


CHAPTER   XVII 
THE  PNEUMOCOCCUS 

THE  pneumococcus,  also  called  the  diplococcus 
lanceolatus,  was  discovered  by  Frankel.  As  its  name 
implies,  the  organism  occurs  usually  in  lance-shaped 
twos.  It  is  not  decolorized  when  stained  according  to 


Blood  corpuscle 


Pneumococci-*:**  •'  *-  Blood  corpuscle 

I 


V  '!  ^Pneumococci 

"•: 


Fig.  33. — Capsulated  pneumococci  in  blood  from  the  heart  of  a  rabbit; 
carbol-fuchsin,  partly  decolorized;  XlOOO  (McFarland). 

Gram's  method,  and  when  occurring  in  sputum  or  blood 
is  usually  surrounded  by  a  thick  gelatinous  capsule. 
The  pneumococcus  is  non-motile  and  does  not  produce 
spores.  It  grows  on  ordinary  media,  but  prefers  those 
to  which  a  little  blood  or  blood-serum  has  been  added. 
102 


THE  PNEUMOCOCCUS  103 

The  pneumococcus  is  closely  allied  to  the  streptococcus, 
from  which  it  is  sometimes  hard  to  distinguish. 

This  is  the  germ  which  is  responsible  for  most  of  the 
cases  of  lobar  pneumonia  and  for  more  than  half  of  the 
other  forms  of  pneumonia.  Other  infections  in  which 
the  pneumococcus  is  frequently  the  causative  agent 
are  pleurisy,  otitis  media,  with  its  complicating  mas- 
toiditis,  meningitis,  endocarditis  (inflammation  of  the 
valves  of  the  heart),  rhinitis  (inflammation  of  the  nasal 
passages),  tonsillitis,  arthritis  (inflammation  of  joints), 
and  conjunctivitis  and  keratitis  (inflammation  of  the 
outer  covering  of  the  eyeball). 

Usually  when  the  pneumococcus  invades  the  lungs  an 
extensive  inflammation  of  the  lungs  results.  If  the  inflam- 
mation involves  an  entire  lobe  or  more  it  is  spoken  of  as 
a  lobar  pneumonia;  when  it  is  scattered  throughout  the 
lung  it  is  called  a  bronchopneumonia. 

In  pneumonia  there  is  a  marked  pouring-out  into  the 
air  spaces  of  leukocytes,  serum,  and  fibrin.  Mixed  with 
this  are  degenerated  epithelial  cells  from  the  air  spaces, 
red  blood-cells,  pneumococci,  and  cell  debris.  The  affected 
lobe  becomes  almost  solid  and  may  be  compared  to  a 
sponge  which  has  been  saturated  with  pus.  There  is  much 
absorption  of  poison  from  all  this  material,  hence  the  high 
fever,  delirium,  rapid  pulse,  etc.  If  the  patient  recovers 
the  lung  gradually  resumes  its  normal  condition,  the  exu- 
date  being  absorbed  and  carried  off  by  the  scavenger  cells 
of  the  body  (white  blood-cells).  Some  of  it,  to  be  sure,  is 
expelled  by  coughing. 

In  pneumonia  the  pneumococci  are  found  in  enormous 
numbers  in  the  sputum;  in  otitis  media,  in  the  pus  dis- 
charged from  the  ear;  in  rhinitis  it  is  in  the  nasal  secre- 


104  APPLIED    BACTERIOLOGY    FOR    NURSES 

tion;  in  tonsillitis,  in  the  exudate  covering  the  tonsils; 
in  conjunctivitis  and  keratitis,  in  the  mucopurulent 
secretion  of  the  eye.  Moreover,  it  has  been  found 
that  the  pneumococcus  is  also  present  in  the  mucus  of 
the  mouth  and  throat  of  very  many  healthy  persons. 

We  see,  therefore,  that  a  great  many  different  sources 
of  infection  must  be  guarded  against.  So  far  as  the  care 
of  pneumonia  patients  is  concerned,  all  the  sputum 
should  be  carefully  disinfected,  and  care  should  be  taken 
that,  in  coughing,  particles  of  sputum  are  not  sprayed 
into  the  air.  In  crowded  rooms  the  inhalation  of  such 
moist  spray  particles  by  others  is  undoubtedly  a  com- 
mon source  of  infection.  Patients  suffering  from  pneu- 
monia are  often  too  ill  to  prevent  their  soiling  their 
lips,  face,  and  hands  with  sputum,  and  the  nurse  should, 
therefore,  be  on  her  guard  to  prevent  further  infection 
from  this  source.  The  enumeration  of  the  main  sources 
of  infection  as  given  above  should  suffice  to  guide  the 
nurse  in  guarding  others  against  pneumococcus  infec- 
tion. It  is  encouraging  to  know  that  the  pneumococcus 
is  very  sensitive  to  germicidal  agents.  Exposed  to  direct 
sunlight  pneumonic  sputum  loses  its  infectivity  after  a 
few  hours.  The  fine  spray  expelled  in  coughing  that 
remains  suspended  in  the  air  soon  dries  so  completely 
that  no  pneumococci  survive  after  two  hours. 


CHAPTER  XVIII 

STREPTOCOCCUS  INFECTIONS 

THE  Streptococcus  pyogenes1  was  observed  by  Koch 
and,  independently,  also  by  Ogston  in  1882,  but  was  first 
isolated  by  Fehleisen  in  1883.  The  cocci  are  spheric  or 


Fig.  34. — Streptococcus  pyogenes,  from  the  pus  taken  from  an  ab- 
scess; X1000  (Frankel  and  Pfeiffer). 


oval,  and  occur  in  chains  of  eight,  ten,  twenty,  or  more 
individuals,  though  often  merely  in  pairs.  They  stain 
readily  with  the  ordinary  stains,  and  retain  the  color 


1  Pyogenes  means  "  pus  producer." 


105 


106  APPLIED   BACTERIOLOGY  FOR  NURSES 

when  treated  according  to  Gram's  method.  They 
grow  readily  on  various  media,  but  prefer  media  con- 
taining blood  or  blood-serum.  Many  varieties  of 
streptococci  have  a  peculiar  dissolving  effect  on  blood, 
so  that,  when  grown  on  solid  media  containing  blood, 
each  colony  is  seen  to  be  surrounded  by  a  clear  zone. 
We  speak  of  such  varieties  as  "hemolyzing"  (blood- 
dissolving)  streptococci. 

Streptococcus  pyogenes  is  the  cause  of  a  great  variety 
of  infections  in  man.  Among  these  may  be  mentioned 
erysipelas,  cellulitis,  sepsis,  puerperal  infection,  acute 
peritonitis,  tonsillitis,  bronchopneumonia,  otitis  media, 
and  its  complicating  mastoiditis,  meningitis,  enteritis, 
endocarditis,  synovitis,  and  arthritis.  It  must  not  be 
understood,  however,  that  these  infections  are  always 
due  to  streptococcus  pyogenes,  for  we  have  already 
learned  that  other  bacteria  may  be  the  cause.  A  number 
of  observers  hold  that  scarlet  fever  is  a  streptococcus 
infection,  but  the  general  opinion  is  that  this  organism 
is  merely  a  secondary  invader,  probably  through  the 
tonsils. 

The  Streptococcus  pyogenes,  fortunately,  is  not  dif- 
ficult to  kill.  Thus,  an  exposure  to  a  temperature 
of  130°  F.  for  from  ten  to  twenty*  minutes  ordinarily 
suffices.  Bichlorid  of  mercury,  1:5000,  carbolic  acid, 
1  per  cent.,  lysol,  J  per  cent.,  kill  the  germ  in  a  few 
minutes. 

It  should  be  unnecessary  to  enumerate  all  the  pre- 
cautions which  a  nurse  should  take  in  preventing  the 
spread  of  streptococcus  infection  to  others.  They 
will  differ,  of  course,  with  the  kind  of  infection  one  is 
dealing  with.  It  is  well  to  remember,  however,  that 


STREPTOCOCCUS   INFECTIONS  107 

transmission  is  probably  always  direct,  and  that  infec- 
tion through  the  air  is  very  unlikely.  For  this  reason, 
it  is  unreasonable  to  insist  on  isolating  cases  of  erysipelas 
while  keeping  cases  of  puerperal  sepsis  in  the  ward. 
In  fact,  so  long  as  the  skin  remains  unbroken  in  the 
former  condition,  there  is  not  much  likelihood  of  trans- 
mission to  others.  The  most  virulent  streptococci  are 
those  coming  immediately  from  septic  infections. 
Owing  to  the  extreme  susceptibility  of  women  directly 
after  childbirth  to  infection  by  way  of  the  inner  raw 
surface  of  the  uterus,  it  is  imperative  that  no  nurse  who 
has  just  before  been  in  contact  with  streptococcus  in- 
fections, or  even  with  pus  of  any  kind,  be  allowed  to  care 
for  obstetric  cases. 

An  antistreptococcus  serum,  obtained  by  injecting 
horses  repeatedly  with  various  cultures  of  Streptococcus 
pyogenes,  has  been  used  in  the  treatment  of  streptococcus 
infections.  The  results,  as  reported  by  different  ob- 
servers, are  variable,  but  in  certain  cases  appear  to  be 
good.  The  dose  of  the  serum  is  large,  from  50  to  100  c.c. 
or  more  intravenously,  is  usually  recommended.  Moser, 
of  Vienna,  uses  the  serum  extensively  in  the  treatment  of 
severe  cases  of  scarlet  fever,  and  claims  good  results. 
The  treatment  of  streptococcus  infections  by  means  of 
bacterial  vaccines  has  yielded  rather  favorable  results 
in  the  hands  of  some  observers. 

Years  ago  it  was  noted  that  malignant  tumors  some- 
times tended  to  disappear  or  at  least  improve  in 
persons  who  had  recovered  from  accidental  erysipelas. 
This  led  to  the  artificial  production  of  erysipelas  in  such 
cases  by  the  inoculation  of  pure  cultures  of  streptococcus. 
Later  on,  only  their  toxic  products  were  employed. 


108  APPLIED   BACTERIOLOGY   FOR   NURSES 

Coley,  of  New  York,  has  obtained  some  striking  results 
in  the  treatment  of  inoperable  sarcoma  by  injections 
of  the  mixed  toxins  of  the  streptococcus  and  the  Bacillus 
prodigiosus.  The  injected  fluid  is  usually  spoken  of  as 
"Coley's  mixed  toxins."  This  treatment  is  advised  only 
in  inoperable  cases. 


CHAPTER  XIX 

STAPHYLOCOCCUS  INFECTIONS 

THE  staphylococcus  was  first  observed  by  Pasteur  in 
1880;  and  first  carefully  studied  in  pure  culture  by 
Rosenbach  in  1884.  As  seen  in  colonies,  the  organism 
appears  orange,  white,  or  lemon  yellow,  and  is,  there- 
fore, divided  into  varieties  termed  respectively  Staphy- 
lococcus aureus,  Staphylococcus  albus,  and  Staphylo- 
coccus citreus.  The  individual  organisms  are  small 
spheric  bodies,  which  usually  group  themselves  in 
irregular  masses.  They  stain  well  with  the  ordinary 
stains,  and  do  not  decolorize  when  treated  according 
to  Gram's  method.  They  grow  well  even  at  room  tem- 
perature, and  do  not  demand  any  special  media.  When 
grown  on  gelatin  they  cause  liquefaction  of  the  medium. 

The  staphylococcus  is  much  more  resistant  than 
other  non-spore-bearing  bacteria.  Cultures  may  some- 
times be  heated  for  an  hour  to  140°  F.  without  killing 
all  the  organisms.  Dried  pus  contains  living  staphylo- 
cocci  for  weeks  and  even  months,  and  they  can  be  found 
alive  in  the  dust  of  air  almost  everywhere.  To  kill  the 
organism  in  pus  with  bichlorid  of  mercury,  1:1000, 
requires  an  exposure  of  several  hours. 

The  most  common  bacterial  excitants  of  acute  ab- 
scesses in  man  are  the  Staphylococcus  and  the  Strep- 
tococcus pyogenes,  though,  of  course,  other  bacteria 
may  also  produce  abscesses.  The  Staphylococcus  albus 

109 


110  APPLIED   BACTERIOLOGY   FOR  NURSES 

appears  to  be  an  almost  constant  inhabitant  of  the 
skin,  and  to  be  the  common  cause  of  "stitch  abscess." 
In  contrast  to  most  other  pathogenic  bacteria,  the 
staphylococcus  appears  to  be  able  to  infect  through 
the  unbroken  skin.  The  organism  has  also  been  found 
in  various  pustular  affections  of  the  skin  and  mucous 
membranes,  in  acute  abscess  in  the  lymph-glands,  in 
empyema,  endocarditis,  septicemia,  and  pyemia.  Boils 
and  carbuncles  are  very  frequently  due  to  this  organism. 


jt^ 

Fig.  35. — Staphylococcus  pyogenes  aureus  (Gtinther) . 

So  far  as  a  source  of  infection  of  others  is  concerned, 
we  really  need  not  worry  much  about  the  occurrence  of 
the  staphylococcus  in  the  dust  in  air.  Lister,  it  will  be 
remembered,  kept  a  spray  of  carbolic  acid  solution 
playing  about  the  operating-room  during  surgical 
operations  in  order  to  kill  the  germs  which  might  be 
present  in  the  air.  Experience,  however,  soon  showed 
that  this  was  unnecessary.  The  presence  of  the  staphy- 
lococcus on  the  skin  is  of  more  importance,  but  this,  too, 


STAPHYLOCOCCUS  INFECTIONS  111 

presents  no  great  obstacle  in  controlling  infection. 
The  main  point  to  bear  in  mind,  in  guarding  against 
the  spread  of  these  infections,  is  the  high  resistance  of  the 
organism,  especially  in  pus,  and  this  indicates  careful 
attention  on  the  nurse's  part,  chiefly  to  the  sterilization 
of  instruments,  hypodermic  needles,  and  the  like. 

In  recent  years  considerable  success  has  attended  the 
treatment  of  abscesses,  boils,  and  other  localized  staphy- 
lococcus  infections  by  means  of  bacterial  vaccines. 
The  doses  ordinarily  employed  are  from  300,000,000  to 
500,000,000  dead  staphylococci  suspended  in  salt 
solution.  The  injections  are  given  at  intervals  of  about 
five  or  six  days. 


CHAPTER  XX 

THE  MENINGOCOCCUS 

THE  meningococcus,  also  called  the  Diplococcus  intra- 
cellularis  meningitidis,  was  discovered  by  Weichsel- 
baum  in  1887.  It  is  a  somewhat  flattened  organism, 
occurring  mostly  in  twos  (diplococcus),  and  occasionally 
in  small  chains  of  fours.  When  stained  according  to 
Gram's  method  it  decolorizes;  that  is,  it  is  Gram-nega- 
tive. It  does  not  grow  well  except  on  media  to  which 
blood-serum  or  ascitic  fluid  has  been  added.  The 
organism  is  not  very  resistant,  and  dies  readily  on  dry- 
ing or  on  exposure  to  direct  sunlight. 

The  meningococcus  is  the  cause  of  epidemic  cerebro- 
spinal  meningitis.  Other  forms  of  meningitis  are  caused 
by  the  tubercle  bacillus,  by  the  pneumococcus  and 
streptococcus,  and  occasionally  also  by  other  bacteria. 
In  epidemic  cerebrospinal  meningitis  the  meningococcus 
is  found  in  the  purulent  exudate  covering  the  meninges 
and  in  the  cerebrospinal  fluid  drawn  by  means  of  lumbar 
puncture.  In  fact,  it  is  only  by  means  of  lumbar  punc- 
ture that  the  variety  of  meningitis  present  can  be  deter- 
mined. 

It  has  also  been  found  that  the  meningococcus  is 
present  in  the  nasal  secretions  of  patients  suffering  from 
epidemic  cerebrospinal  meningitis,  and  in  the  nasal 
secretions  of  about  10  per  cent,  of  the  persons  in  inti- 
mate contact  with  such  patients.  The  exact  mode  of 
112 


THE   MENINGOCOCCUS 


113 


infection  is  not  known,  but  is  probably  through  infected 
nasal  secretions.  This,  of  course,  indicates  the  measures 
which  should  be  taken  in  order  to  prevent  the  spread  of 
the  disease  to  others. 

Epidemic  cerebrospinal  meningitis  has  been  treated 
with  specific  antimeningococcus  serum,  obtained  by  in- 
jecting horses  with  cultures  of  the  meningococcus. 


Fig.  36. — Meningococcus  in  pus  cells:  Pus  cells  containing  dip- 
lococci  from  the  meninges.  A  few  diplococci  are  in  the  exudate 
outside  of  the  pus  cells.  Between  the  pus  cells  there  are  delicate 
fibrillae  of  fibrin.  The  illustration  is  an  accurate  representation  of  a 
group  of  cells  in  the  field  of  the  microscope  (Councilman) . 

The  serum  is  injected,  by  means  of  lumbar  puncture,  into 
the  spinal  canal,  and  the  results  thus  obtained  have  been 
very  encouraging,  the  death-rate  being  but  one-half  that 
of  cases  not  so  treated.  As  in  all  treatment  with  a 
specific  sera,  it  is  useless  to  employ  antimeningococcus 
serum  in  cases  of  meningitis  produced  by  germs  other 
than  the  meningococcus.  It  is  important,  therefore, 
before  employing  the  serum  to  make  sure  that  the 


114  APPLIED  BACTERIOLOGY   FOR  NURSES 

case  is  really  one  of  meningococcus  meningitis.  This, 
as  already  stated,  is  done  by  means  of  lumbar  puncture. 
The  fluid  thus  obtained  is  centrifuged,  the  sediment 
spread  on  a  slide,  dried,  fixed,  and  then  stained  ac- 
cording to  Gram's  method.  In  case  of  meningococcus 
meningitis  Gram-negative  diplococci  will  be  found 
mostly  in  the  interior  of  pus  cells.  (See  Fig.  36, 
page  113.)  If  the  organisms  are  Gram-positive  the  case 
is  not  one  of  meningococcus  meningitis. 


CHAPTER  XXI 

THE  GONOCOCCUS 

THE  micrococcus  of  gonorrhea  was  discovered  by 
Neisser  in  1879.  It  is  a  small  coccus,  occurring  in  pairs 
(diplococcus).  The  two  organisms  which  form  the  pair 
are  flattened  on  their  adjacent  sides,  which  gives  to  the 
organism  somewhat  the  appearance  of  a  coffee  bean. 
When  stained  by  Gram's  method  the  gonococcus  is 


Fig.  37. — Gonococci  in  urethral  pus  (McFarland). 

decolorized,  i.  e.,  it  is  "Gram-negative."  It  can-  only 
with  difficulty  be  grown  on  artificial  media,  but  thrives 
fairly  well  on  glucose  agar  to  which  either  blood  or 
ascitic  fluid  has  been  added.  Quick  drying  destroys  it, 
and  it  cannot  resist  a  temperature  of  45°  C.  more  than  a 
few  minutes.  But  in  thick  smears,  on  linen,  etc.,  it 
has  been  found  alive  after  a  lapse  of  seven  weeks. 

115 


116  APPLIED   BACTERIOLOGY   FOR  NURSES 

The  gonococcus  is  the  cause  of  various  severe  purulent 
inflammations,  among  which  the  most  important  are 
gonorrheal  urethritis  and  vaginitis  and  gonorrheal 
ophthalmia,  as  well  as  chronic  joint  affections  and 
chronic  endocarditis.  In  adults  ophthalmia  is  usually 
due  to  an  indirect  infection,  through  soiled  towels,  etc., 
but  in  newborn  babies  it  is  caused  by  direct  inoculation 
with  gonococci  found  in  the  vaginal  discharge  of  the 
mother.  As  a  prophylactic  measure  the  use  of  a  2  per 
cent,  solution  of  silver  nitrate  in  the  eyes  of  every  new- 
born baby  has  become  a  routine  practice  in  obstetrics, 
with  the  result  that  the  number  of  cases  of  blindness 
due  to  gonorrheal  ophthalmia  neonatorum  has  mate- 
rially diminished. 

In  smears  of  fresh  pus  many  of  the  gonococci  will  be 
found  within  the  pus  cells,  and  this  peculiarity,  together 
with  their  behavior  toward  Gram's  stain,  are  aids  in  the 
diagnosis.  (The  meningococcus  in  pus  from  meningitis 
gives  a  similar  picture,  but  it  is  smaller  than  the  gono- 
coccus, and  does  not,  as  a  rule,  occur  under  the  same 
conditions.) 

The  gonococcus  may  remain  dormant  in  the  vagina 
and  urethra  for  years,  and  at  any  time  set  up  a  fresh 
acute  process.  A  vaccine,  prepared  by  suspending  the 
killed  gonococcus  in  an  indifferent  fluid  (physiologic 
salt  solution),  has  apparently  given  good  results  in  some 
joint  lesions.  The  dose  varies  from  20,000,000  to  1,000,- 
000,000,  repeated  at  intervals  of  three  to  seven  days. 
Attempts  have  been  made  to  produce  a  curative  serum 
by  inoculating  horses  with  increasing  doses  of  vaccine, 
but  so  far  the  results  of  its  use  have  not  been  specially 
satisfactory. 


CHAPTER  XXII 

SYPHILIS 

IT  was  not  until  1904  that  the  causative  micro-or- 
ganism of  syphilis  was  discovered,  and  not  until  1911 
was  it  successfully  cultivated  on  artificial  media.  The 
organism  belongs  to  the  class  known  as  Treponema, 
and  in  shape  resembles  a  cork-screw.  The  organism 
stains  with  difficulty.  For  rapid  examinations  the  so- 
called  "ultramicrosccpe,"  or  microscope  with  dark- 
field  illumination,  is  usually  employed.  The  picture 
thus  produced  is  shown  in  Fig.  38.. 

Acquired  syphilis  begins  with  a  characteristic  sore 
known  as  a  chancre  or  hard  chancre.  If  the  disease 
has  been  acquired  through  sexual  intercourse  the  sore 
appears  on  the  genitals.  The  stage  of  chancre  is  also 
spoken  of  as  the  primary  stage.  It  lasts  about  six 
to  eight  weeks,  and  is  followed  by  the  secondary  stage. 
The  symptoms  of  the  secondary  stage  include  a  rash, 
sore  throat,  pains  in  the  joints,  falling  out  of  the  hair, 
etc.  The  duration  of  this  stage  is  variable,  and  no  hard- 
and-fast  line  can  be  drawn  between  it  and  the  tertiary 
stage.  During  the  latter  the  disease  shows  a  tendency 
to  produce  certain  skin  eruptions,  gummatous  growths  in 
the  viscera,  and  degenerations. 

The  ulcerations,  especially  the  primary  sore  (chancre), 
and  the  so-called  "mucous  patches"  in  the  mouth  and 

117 


118  APPLIED   BACTERIOLOGY   FOR   NURSES 

throat,  are  exceedingly  infectious.  Examined  with 
the  dark-field  microscope,  scrapings  from  these  ulcera- 
tions  are  seen  to  swarm  with  the  Treponema  pallidwn. 
A  syphilitic  having  mucous  patches  may  infect  a  drink- 
ing-cup  or  a  spoon  and  cause  infection  of  others.  The 
infection  then  makes  its  appearance  on  the  lip  or  tongue 
of  the  victim.  Infection  may  also  be  carried  through 
kissing, 


Fig.  38. — Treponema  pallidum  appearing  as  bright  refractive 
body  on  a  dark  field,  as  shown  by  India  ink  or  ultramicroscope 
(Park  and  Williams). 

When  syphilis  is  transmitted  from  parent  to  offspring, 
the  disease  often  shows  itself  in  the  baby  by  what  are 
called  "snuffles."  The  secretion  from  the  nose  of  such 
babies  is  highly  infectious.  A  syphilitic  baby  should 
not  be  given  to  a  healthy  wet-nurse  to  suckle.  If  the 
mother  cannot  nurse  it,  the  baby  should  be  brought  up 
on  the  bottle. 


SYPHILIS  119 

A  great  aid  in  the  diagnosis  of  syphilitic  infections  is 
that  devised  by  Wassermann,  of  Berlin.  This  test  can 
be  performed  either  on  the  blood  or  the  cerebrospinal 
fluid  of  patients.  While  a  positive  result  indicates  a 
syphilitic  infection,  a  negative  result  does  not  indicate 
the  absence  of  such  infection. 


CHAPTER  XXIII 

EXANTHEMATA1 

UNDER  this  head  are  included  measles,  German 
measles,  scarlet  fever,  small-pox,  chicken-pox,  and 
typhus  fever.  They  are  alike,  in  that  no  specific  organ- 
ism has  yet  been  demonstrated  and  definitely  proved  to 
be  the  cause  of  the  infection.  The  causative  agent  is 
spoken  of  as  a  " virus,"  and  typic  clinical  symptoms 
can  be  produced  in  healthy  animals  or  humans  by  in- 
oculation with  skin  or  blood  from  patients  ill  with  one 
of  the  exanthematous  diseases. 

Scarlet  Fever. — In  1904  Mallory  described  tiny 
glistening  corpuscles  in  tissue  cells  which  he  regarded 
as  the  protozoan  causes  of  scarlet  fever.  Other  ob- 
servers were  unable  to  demonstrate  them  in  living  tis- 
sues, but  found  them  also  in  measles'  blisters  and  in  some 
antitoxin  rashes.  They  are  now  generally  regarded  as 
degenerated  leukocytes. 

Very  recently  (March,  1916)  Mallory  reports  isolating 
from  the  tissues  of  children  dying  early  in  the  course  of 
the  disease,  especially  from  the  tonsils,  fauces,  root  of  the 
tongue,  trachea  and  lungs,  a  strongly  Gram-positive  bacil- 
lus growing  between  the  epithelial  cells.  In  form  it  varies 
from  coccus-like  to  large  bacillary  organisms.  He  believes 
that  this  is  the  cause  of  scarlet  fever,  and  has  accordingly 

1  Exanthemata,  the  plural  of  exanthem  =   a  breaking  out,  an 
eruption. 
120 


EXANTHEMATA  121 

named  it  provisionally  Bacillus  scarlatina.  It  produces 
a  poison  which  causes  necrosis  and  denudation  of  the 
covering  epithelium  and  leads  to  an  exudation  of  serum 
and  leukocytes. 

The  results  reported  have  not  yet  been  confirmed;  if 
they  are,  this  represents  a  most  important  discovery. 

The  streptococci  which  cause  the  severe  sore  throats  in 
scarlet  fever  are  by  most  bacteriologists  considered  as  a 
constant  but  secondary  infection,  and  not  as  the  cause  of 
the  general  symptoms  and  of  the  rash  of  scarlatina. 

Measles  and  German  Measles. — Bodies  similar  to 
Mallory's  scarlet  fever  bodies  have  been  described,  and 
an  influenza-like  bacillus  has  been  held  responsible  for 
the  coryza  which  accompanies  measles,  but  nothing 
definite  has  been  proved  about  the  bacteriology  of  these 
two  diseases. 

The  virus  of  measles,  whatever  its  nature,  exists  in 
the  blood  of  the  patient  during  the  fever.  This  has 
been  demonstrated  by  several  investigators,  who  have 
succeeded  in  producing  the  disease  in  monkeys  by  in- 
oculating these  animals  with  the  blood  of  measles 
patients.  After  the  fever  abated  the  blood  was  no  longer 
infectious.  In  monkeys  the  disease  runs  a  milder  course 
than  in  human  subjects,  and  a  monkey  that  has  passed 
through  one  attack  is  thereby  made  immune. 

The  virus  passes  through  a  Berkefeld  filter,  that  is, 
the  filtered  material  remains  infectious.  It  is  destroyed 
by  heating  to  55°  C.  for  fifteen  minutes,  but  resists 
drying  for  twenty-four  hours.  No  development  takes 
place  on  any  of  the  usual  culture-media. 

Bacteriologists  have  found  cocci  and  bacilli  which 
for  a  time  were  considered  the  causes  of  the  disease. 


122 


APPLIED    BACTERIOLOGY   FOR   NURSES 


We  know,  now  that  these  were  accidental  contaminations. 
Weigert  also  described  "bodies"  included  in  epithelial 
cells,  which  have  since  been  variously  interpreted  as  de- 
generative forms  of  tissue  cells,  or  as  protozoa  causing 
the  disease. 


Fig.  39. — Operating-room.  Collecting  vaccine  from  a  calf.  The 
calves  which  are  used  hi  the  preparation  of  the  virus  are  first 
washed,  the  long  hair  is  clipped,  and  the  skin  is  cleaned  with 
bichlorid  solution,  then  hi  an  alkaline  bath,  and  finally  all  traces 
of  the  antiseptics  are  removed  by  thorough  rinsing  in  sterile  water, 
after  which  the  surface  to  be  operated  upon  is  shaved.  The  ani- 
mals are  then  conveyed  to  the  operating-room,  where  they  are 
vaccinated  with  tested  virus  under  conditions  similar  to  those  ex- 
isting in  the  operating-rooms  of  modern  hospitals,  after  which  they 
are  transferred  to  the  propagating  stable  and  kept  as  clean  as  is 
possible.  In  about  six  days  the  virus  is  removed  and  prepared  for 
use  under  rigid  aseptic  precautions.  (Courtesy  of  H.  K.  Mulford 
Company,  Phila.) 

Cow-pox  is  presumably  identical  with  small-pox, 
being  modified  because  it  develops  in  a  different  host. 
When  calves  are  inoculated  with  small-pox  virus  they 


EXANTHEMATA  123 

develop  lesions  very  similar  to  cow-pox.  In  monkeys 
inoculation  with  cow-pox  virus  protects  against  small- 
pox, and  vice  versa,  and  the  same  protective  action 
holds  in  man.  This  has  been  proved  for  more  than  a 
century — i.  e.,  since  Jenner,  in  1796,  introduced  vaccina- 
tion. In  every  country  where  vaccination  has  been  made 
compulsory  there  has  been  a  sudden  and  constant  lower- 
ing of  the  number  of  small-pox  cases,  and  those  which  do 
occur  are  of  a  milder  nature  than  formerly. 


CHAPTER  XXIV 

FILTERABLE  VIRUSES 

IN  describing  bacteria  it  was  stated  that  they  varied 
in  size  from  5^00  to  ^  inch;  the  average  pathogenic 
bacterium  is  about  10^00  mcn  l°ng-  It  is  obvious  that 


a  b  c  d 

Fig.  40. — Different  types  of  bacteriologic  filters:     a,  Kitasato;  6, 
Berkefeld;  c,  Chamberland;  d,  Reichel  (McFarland). 

such  tiny  organisms  readily  pass  through  ordinary  paper 
filters  and  through  absorbent  cotton  filters.  It  is  pos- 
sible, however,  to  construct  filters  which  entirely  hold 

124 


FILTERABLE    VIRUSES  125 

back  even  such  tiny  particles  as  bacteria.  Such  filters 
are  usually  made  of  an  unglazed,  burnt  clay.  A  number 
of  different  makes  are  on  the  market — Berkefeld, 
Pasteur,  Chamberland,  Pukall,  etc.  In  all  of  these  it  is 
necessary  to  either  draw  the  fluid  through  by  suction  or 
force  it  through  by  pressure.  Figure  40  shows  the  con- 
struction of  this  type  of  filter. 

Experiments  conducted  with  filters  of  this  type  led 
to  the  astonishing  discovery  that  the  virus  of  certain 
infectious  diseases  was  able  to  pass  through.  It  was 
impossible  to  see  any  living  particles  in  these  filtrates 
even  with  the  highest  powers  of  the  microscope,  and  yet 
the  virus  was  present,  as  could  be  shown  by  appropriate 
animal  experiments.  Very  little  is  known  about  the 
nature  of  these  filterable  viruses,^  but  we  have  felt  it  well 
to  mention  the  fact  that  they  exist.  Some  of  the  dis- 
eases known  to  be  caused  by  a  filterable  virus  are: 

Measles. 

Hydrophobia  (rabies). 

Poliomyelitis. 

Yellow  fever. 

Dengue. 

Foot-and-mouth  disease  of  cattle. 

Rinderpest  of  cattle.   - 

Hog  cholera. 

So  far  as  hydrophobia  is  concerned,  it  appears  that 
some  of  the  finer  grained  porcelain  filters  hold  back  the 
virus.  Certain  characteristic  bodies  found  in  the  brain 
cells  of  rabid  animals  are  diagnostic  of  the  disease. 
They  are  spoken  of  as  "Negri  bodies/'  and  are  held  by 
some  observers  to  be  the  causative  organisms,  i.  e,, 
the  virus. 


CHAPTER  XXV 

MALARIA 

MALARIA  is  an  infectious  disease,  the  cause  of  which 
is  not  a  bacterium,  but  an  animal  micro-organism,  a  pro- 
tozoon  (plural  protozoa).  Its  old  name,  "plasmodium 
malarise,"  has  been  replaced  by  the  term  "hemameba 
malarise."  This  parasite  was  discovered  in  1880  by 
Laveran,  a  French  army  surgeon,  and  in  the  course 
of  work  with  the  malarial  parasite  which  followed  upon 
Laveran's  discovery,  Manson,  Ross,  Grassi,  and  others 
found  that  the  hemameba  has  two  distinct  life-cycles, 
a  sexual  one,  which  takes  place  in  mosquitos,  and  a 
non-sexual  cycle,  occurring  in  the  blood  of  human 
patients.  The  young  forms  of  hemameba,  both  male 
and  female,  live  in  the  Anopheles,  a  species  of  mosquito 
which  breeds  and  lives  largely  in  stagnant  pools  and 
marshes.  In  the  stomach  wall  of  this  mosquito  fer- 
tilization occurs,  and  the  development  of  the  young 
forms  proceeds  until,  at  the  end  of  ten  to  fourteen  days, 
they  are  set  free  into  the  digestive  tract  of  the  mosquito 
and  pass,  through  the  bite  of  the  insect,  into  the  blood- 
stream of  a  human  being.  Here  they  penetrate  the  red 
corpuscles,  where  they  remain  until  they  are  fully 
matured,  and  divide  into  a  number  of  round  or  oval 
segments,  which  are  shed  into  the  blood-stream.  The 
same  cycle  can  be  repeated  indefinitely  in  man,  the 
stage  of  fever  marking  the  setting  free  of  amebulae. 

126 


PLATE  II 


o 


JO  II  J2 

MALARIAL  PARASITES:  1  TO  10  INCLUSIVE,  TERTIAN  PARASITES; 
11  AND  12,  QUARTAN  PARASITES.  (Deaderick,  "Study  of  Malaria.") 

1.  Normal  rod  blood  cell.  2.  Young  tertian  ring.  3.  Large  ter- 
tian ring.  4.  Half-grown  tertian  parasite.  5.  Infected  cell  showing 
Schiiffner's  dots.  6.  Adult  tertian  parasite.  7.  Beginning  sporu- 
lation.  8.  Sporulation  completed.  9.  Tertian  mierogamotocyte. 
10.  Tertian  macrogamete.  11.  Young  quartan  ring.  12.  Older 
quartan  ring. 


MALARIA  127 

Although  it  is  possible,  experimentally,  to  produce 
malaria  by  inoculating  a  person  with  blood  from  a 
patient  suffering  from  the  disease,  yet,  in  practice, 
malaria  can  never  be  transmitted  without  the  aid  of 
the  particular  mosquitos  mentioned.  In  other  words, 
without  mosquitos  there  can  be  no  spread  of  malaria. 

There  are  three  recognized  types  of  the  hemameba — 
the  quartan,  the  tertian,  and  the  estivo-autumnal 
parasite.  The  two  former  cause  a  relatively  benign 
infection,  while  the  estivo-autumnal  parasite  causes 
malignant  malaria.  (Plate  II.) 

The  organism  of  the  quartan  malaria  develops  in  the 
blood  in  seventy-two  hours;  hence,  there  is  a  febrile 
stage  every  third  day.  Under  the  microscope,  in  a 
fresh  smear,  the  organism  is  a  tiny  refractive  body, 
slightly  motile,  and  contains  coarse,  blackish-brown 
pigment.  It  segments  into  six  to  twelve  round  amebulse. 

The  tertian  parasite  is  less  glistening,  but  more  ac- 
tively motile  than  the  quartan;  its  cycle  in  the  human 
host  is  completed  in  forty-eight  hours,  and  it  then 
divides  into  fifteen  to  twenty  oval  bodies.  The  pigment 
of  the  tertian  parasite  is  yellowish  brown  and  quite  fine. 

Estivo-autumnal  parasites  are  small  and  show  more 
active  ameboid  motion  than  the  other  two;  they  contain 
very  little  pigment,  which  is  dark  and  quite  fine.  The 
red  blood-corpuscles  which  contain  the  parasite  are  apt 
to  shrink  and  assume  a  brassy  color.  This  type  com- 
pletes its  cycle  chiefly  in  the  blood  of  the  internal  organs 
(e.  g.,  the  spleen),  and  it  may  be  difficult  to  locate  it  at 
all  in  the  circulation.  Its  sexual  forms  are  crescentic  in 
shape.  All  three  types  are  best  stained  with  methylene- 
blue.  The  Romanowsky  method  uses  a  compound  ob- 


128  APPLIED   BACTERIOLOGY    FOR   NURSES 

tained  by  bringing  together  methylene-blue  and  water- 
soluble  eosin;  the  resulting  powder  is  soluble  only  in 
alcohol;  it  stains  the  parasites  blue,  red  blood-cells  a 
deep  pink,  and  white  blood-cells  pale  pink  with  blue 
nucleus. 

Apparently  there  exists  a  slight  natural  immunity 
to  malaria;  occasionally  a  few  residents  in  malarial  dis- 
tricts escape  infection.  Also  a  partial  immunity  is 
acquired  by  some  individuals  who  have  passed  through 
one  or  more  infections.  Thus  the  negroes  on  the  west 
coast  of  Africa  are  less  severely  attacked  than  Euro- 
peans who  go  to  live  there,  and  Koch  has  attributed 
this  to  their  having  acquired  a  partial  immunity  during 
childhood. 

The  malarial  parasites  are  actively  destroyed  by 
quinin,  arsenic,  and  certain  other  substances.  In  the 
campaign  in  this  climate  against  malaria  it  is  well  to 
direct  attention  also  to  suppressing  the  mosquito 
nuisance,  and,  hand  in  hand  with  that,  to  kill  the  malarial 
parasites  in  their  human  hosts  by  means  of  quinin. 

YELLOW  FEVER 

Although  the  specific  organism  of  yellow  fever  has  not 
yet  been  identified,  it  may  be  well  to  mention  the  disease 
here,  because,  like  malaria,  it  requires  a  particular  kind  of 
mosquito  (Stegomyia  calopus)  for  its  transmission  from 
man  to  man.  The  disease  is.  not  conveyed  by  fomites. 
The  bite  of  an  infected  mosquito  does  not  become  infectious 
until  twelve  days  after  it  has  bitten  the  first  patient. 
There  is  a  definite  time  between  the  bite  of  the  mosquito 
and  the  infectivity  of  the  patient's  blood  (average  five 
days),  and  a  definite  time  the  blood  remains  infective 


TRYPANOSOMIASIS  129 

(three  days).  The  blood  during  these  three  days  is  still 
infective  after  passing  through  the  finest-grained  porcelain 
filters.  (See  page  124.) 

Competent  authorities  incline  to  the  belief  that  the 
organism  of  yellow  fever  is  a  protozoon,  i.  e.,  a  unicellular 
animal  micro-organism. 

TRYPANOSOMIASIS 

In  connection  with  malaria  and  yellow  fever  a  word 
may  be  said  about  trypanosomiasis  or  "sleeping-sickness." 
This  dreaded  African  scourge  is  caused  by  a  protozoon 
somewhat  similar  to  that  of  malaria,  and  transmitted  not 
by  the  mosquito,  but  by  a  species  of  biting-fly,  known  as 
the  "tsetse  fly."  The  characteristic  symptoms  are  pro- 
duced by  the  trypanosomes  entering  and  growing  in  the 
cerebrospinal  fluid.  The  disease  appears  to  be  almost  in- 
variably fatal. 


CHAPTER  XXVI 

BACTERIOLOGY  OF  MILK 

MILK,  one  of  the  most  important  articles  of  human 
diet,  is  at  the  same  time  an  excellent  medium  for  the 
growth  and  development  of  bacteria;  hence,  great  im- 
portance attaches  to  methods  pursued  at  the  dairy. 
The  bacteria  generally  found  in  milk  have  two  sources — 
they  may  be  derived  from  the  cow's  udder,  or  they  may 
fall  into  the  milk  while  it  is  being  drawn,  or  later  at  any 
stage  of  handling.  It  is  practically  impossible,  even 
under  the  very  best  conditions  at  the  farm  and  with  the 
most  approved  methods  of  distribution,  to  obtain  a 
milk  absolutely  free  from  bacteria.  But,  fortunately, 
the  varieties  generally  found  in  market  milk  are  not 
pathogenic,  and  are  not  to  be  considered  dangerous  to 
the  consumer  unless  /they  are  allowed  to  multiply  abun- 
dantly, when  they  caitse  souring  and  curdling  or  putre- 
faction, and  may  thus  render  the  milk  unfit  for  use. 

Grading  the  Milk  Supply. — Broadly  speaking,  we  may 
divide  market  milk  into  three  groups: 

(a)  Best  quality,  showing  not  over  10,000  bacteria 
to  the  cubic  centimeter. 

(&)  Good  quality,  not  over  500,000  bacteria  per  cubic 
centimeter. 

(c)  Poor  quality,  5,000,000  to  50,000,000 1  and  more 
bacteria  per  cubic  centimeter. 

In  summer  these  normal  milk  bacteria  multiply 
with  astonishing  rapidity,  and  soon  render  the  milk 

130 


BACTERIOLOGY   OF   MILK  131 

unfit  for  food.  In  addition  to  the  curdling  and  the 
souring,  there  are  produced  by  some  of  these  bacteria 
toxic  substances  which  are  especially  badly  borne  by 
infants,  and,  as  it  is  chiefly  as  an  infant  food  that  milk 
must  be  considered,  it  becomes  necessary  to  devise  means 
of  keeping  the  milk  sweet. 

Safeguarding  the  Milk  Supply  by  Pasteurization. — 
Much  can  be  done  at  the  dairy,  by  keeping  stables  and 
animals  very  clean,  and  by  using  due  precautions  when 
milking  to  keep  out  dust  and  dirt.  Then,  the  warm  milk 
must  be  rapidly  cooled  to  about  40°  to  50°  F.,  bottled, 
and  shipped  in  ice  to  the  consumer.  But  such  condi- 
tions prevail  at  comparatively  few  dairies,  and  naturally 
increase  the  cost  of  production  considerably,  bringing 
such  milk  beyond  the  reach  of  the  great  masses.  When, 
therefore,  for  any  reason  the  bacterial  count  of  milk  is 
high,  it  is  best  to  resort  to  sterilizing  by  heat.  This  may 
mean  boiling  for  five  to  ten  minutes.  The  objections 
to  this  are:  First,  the  coagulation  of  some  of  the  pro- 
teins, which  may  render  them  less  digestible,  and, 
second,  a  peculiar  and  rather  unpleasant  taste  and  odor 
which  are  imparted  to  the  milk.  Therefore,  pasteuriza- 
tion has  largely  superseded  boiling.  This  means  heating 
to  140°-160°  F.  for  fifteen  minutes  or  more.  When  done 
on  a  large  scale,  the  milk  to  be  pasteurized  is  allowed  to 
run  in  a  thin  stream  over  a  metal  surface,  which  is 
heated  by  steam  to  the  required  temperature,  or  it  may 
run  through  a  coil  of  tubes,  which  are  kept  in  hot  water, 
bringing  the  temperature  of  all  the  milk  up  to  the  re- 
quired degree.  It  is  important  that  all  the  milk  be  thus 
heated,  since  otherwise  bacteria  remain  alive  in  some 
of  the  milk,  and  will  develop  rapidly  throughout  the 
whole  lot  of  milk.  Commercial  pasteurization  has 


132  APPLIED   BACTERIOLOGY   FOR   NURSES 

certain  disadvantages  as  well  as  advantages.  If  properly 
done,  with  fresh  milk  which  is  then  cooled  rapidly,  the 
pathogenic  bacteria,  such  as  typhoid  and  tubercle 
bacillus,  are  killed,  as  are  also  the  lactic  acid  bacilli, 
which  cause  the  souring  of  milk.  What  remains  alive 
are  the  spore-bearing  varieties.  Among  them  are  the 
putrefactive  organisms,  but  these  are  present  in  small 
numbers  only  and  are  unable  to  develop  at  low  tempera- 
ture. But  it  is  impossible  to  tell  whether  pasteurized 
milk  was  really  fresh  when  heated,  i.  e.,  it  may  have 
been  in  a  tainted  condition  before  pasteurization. 
Normally,  the  lactic  acid  bacilli,  by  altering  the  reac- 
tion of  the  milk,  keep  down  the  growth  of  putrefactive 
organisms,  but  in  heated  milk  the  growth  of  these  latter 
is  unchecked,  and,  unless  carefully  treated,  well  cooled, 
and  kept  cool,  pasteurized  milk  may  have  a  higher  bac- 
terial count  than  a  good  quality  raw  milk.  For  this 
reason  the  pasteurization  of  milk  supplied  by  the 
dealers  should  be  carefully  supervised  by  the  public 
health  authorities. 

Home  Pasteurization. — There  is  no  doubt  that  home 
pasteurization  of  milk  has  been  found  of  considerable  ad- 
vantage, especially  for  infants,  and  several  pasteurizers 
have  been  put  upon  the  market,  the  best  known  among 
them  being  those  of  Arnold  and  of  Freeman. 

A  simple  milk  pasteurizer  for  home  use  consists  of  a 
tin  pail,  having  a  perforated  cover  and  containing  a 
wire  basket,  into  which  are  fitted  eight  nursing  bottles. 
The  water  in  the  pail  is  heated  to  boiling,  the  wire  crate 
is  then  lowered  until  the  bottles  nearly  touch  the  water. 
The  milk  is  steamed  in  the  open  bottles  for  ten  minutes, 
then  the  bottles  are  corked  and  steaming  is  continued 


BACTERIOLOGY   OF   MILK 


133 


another  fifteen  minutes.    After  that  the  milk  is  kept  on 
ice  until  used. 

Freeman's  pasteurizer  consists  of  a  pail  with  a  tight- 
fitting  cover  and  a  removable  rack,  holding  a  number  of 


Fig.  41. — Arnold's  apparatus  for  sterilizing  milk  (Ashton). 

eylindric  metal  cups,  which  receive  the  milk  bottles. 
The  pail  is  filled  with  water  to  a  groove  about  halfway 


Fig.  42. — Apparatus  for  pasteurizing  milk  (Ashton). 

from  the  top  and  the  water  is  brought  to  the  boiling- 
point.  The  milk  bottles  are  then  placed  into  the  metal 
cups  and  are  in  these  surrounded  by  water,  which 


134  APPLIED   BACTERIOLOGY   FOR   NURSES 

serves  as  a  conductor  of  heat.  The  filled  rack  is  im- 
mersed into  the  boiling  water  in  the  pail,  the  pail  is 
removed  from  the  stove,  and  the  cover  replaced.  Within 
ten  minutes  the  temperature  of  both  water  and  milk 
reaches  160°  F.  and  remains  at  that  level  for  about 
twenty  minutes.  Then  the  bottles  are  removed  and 
rapidly  cooled  in  the  water-bath,  or,  better,  the  hot 
water  in  the  pasteurizer  is  replaced  by  cold,  which  is  run 
in  by  means  of  a  rubber  tube  attached  to  the  kitchen 
faucet.  The  milk  is  then  stored  on  ice. 

Milk  as  a  Carrier  of  Disease. — Besides  the  above  bac- 
teria, which  are  inevitable  inhabitants  of  all  market  milk, 
and  which  vary  in  the  different  grades  of  milk  in  number 
only,  other  and  much  more  serious  contaminations  may 
occasionally  be  found.  Of  those  derived  from  the  cow 
the  most  frequent  are  streptococci  from  a  suppurative 
mastitis,  and  the  tubercle  bacilli  from  udder  tuberculosis 
or  tuberculous  lesions  elsewhere.  It  has  been  demon- 
strated that  while  the  tubercle  bacillus  found  in  cows  is 
not  of  the  same  variety  as  that  which  produces  pulmonary 
tuberculosis  in  adults,  it  is  nevertheless  able  to  set  up  even 
fatal  tuberculous  processes  in  small  children  and  infants. 

Typhoid  fever  is  not  infrequently  spread  by  means,  of 
milk;  the  bacillus  is  introduced  into  the  milk  directly, 
through  uncleanly  habits  of  the  milkers,  among  whom 
there  may  be  a  so-called  "carrier/'  that  is,  an  apparently 
perfectly  healthy  individual  who  harbors  in  his  intestines 
virulent  typhoid  bacilli,  or,  indirectly,  by  contaminated 
water  which  has  been  used  to  wash  utensils,  etc. 

Asiatic  cholera,  dysentery,  and  similar  diseases  may 
be  spread  in  the  same  manner,  but  are  probably  only 
infrequently  disseminated  in  this  way.  Epidemics  of 


BACTERIOLOGY   OF   MILK 


135 


scarlet  fever  and  diphtheria,  however,  have  been  di- 
rectly traced  to  contaminated  milk. 

It  is  important  to  keep  flies  from  milk.  A  fly  can 
readily  infect  milk  through  the  filth  which  it  carries  on 
its  legs. 


Fig.    43. — Colonies    of    bacteria    transplanted    by    a    fly's    feet 
(Magruder). 

When  properly  supervised  by  the  health  authorities, 
pasteurization  of  the  milk  offers  the  best  protection 
against  all  these  various  infections.  In  New  York  City 
at  the  present  time  no  milk,  excepting  that  equal  to 
"certified"  grade,  may  be  sold  unless  it  has  been  effectively 
pasteurized. 


CHAPTER   XXVII 

FERMENTED  MILKS 

ACCORDING  to  Metschnikoff,  many  of  the  degenera- 
tive changes  associated  with  old  age  are  due  to  poisons 
generated  in  the  intestines  by  putrefactive  bacteria. 
Moreover,  his  investigations  lead  him  to  believe  that 
excessive  intestinal  putrefaction  can  be  greatly  lessened 
by  introducing  bacilli  which  produce  lactic  acid  in  the 
intestines.  In  fact,  he  ascribes  the  healthfulness  and 
longevity  of  certain  people  of  eastern  Europe  to  their 
extensive  use  of  sour  milk  as  an  article  of  diet. 

For  many  years  the  people  of  eastern  Europe  and 
western  Asia  have  looked  upon  sour  milk  as  an  essential 
part  of  their  daily  diet.  The  term  sour  milk  covers  all 
milks  or  parts  of  milk  in  which  lactic  acid  fermentation 
is  pronounced.  Ordinary  buttermilk  sours  because  of 
the  growth  of  lactic  acid  bacteria  in  the  raw  milk. 
Sour  milk  from  the  dealers  is  more  usually  heated  milk 
to  which  some  special  culture  of  bacteria  ("starter") 
has  been  added.  A  starter,  now  extensively  used,  is  one 
supplied  by  Metschnikoff. 

Many  different  species  of  bacteria  are  able  to  provoke 
the  lactic  acid  fermentation,  but  ordinarily  only  a  few 
species  are  responsible  for  the  natural  souring  of  milk. 
Chief  among  the  latter  are  the  common  lactic  acid  bacilli 
and  an  organism  spoken  of  as  the  milk  streptococcus. 
Inoculation  of  sterilized  milk  with  pure  cultures  of  these 

136 


FERMENTED   MILKS 


137 


two  organisms  and  with  mixtures  reproduces  very  closely 
the  process  of  natural  souring. 

In  addition  to  this  lactic  acid  fermentation,  milk  is 
sometimes  caused  to  undergo  an  alcoholic  fermentation. 
This  is  done  by  fermenting  the  milk  with  yeast  or  with 
a  mixture  of  lactic  acid  bacteria  and  yeast.  A  well- 


Fig.  44.— Bacillus  bulgaricus  of  the  bacillary  milk;  X  1000 
(Fairchild) . 

known  drink,  called  koumiss  (or  kumyss),  is  made  by 
the  Tartars  from  mares '  milk,  a  small  quantity  of  old 
koumiss  often  being  added  to  fresh  milk  as  a  starter. 
In  this  country  koumiss  is  made  commercially  by  fer- 
menting milk  with  yeast  and  lactic  acid  bacilli.  Such 
a  preparation  contains  not  only  lactic  acid,  but  also 
carbonic  acid  gas  and  about  1  per  cent,  of  alcohol. 


138  APPLIED   BACTERIOLOGY   FOR  NURSES 

Matzoon,  yoghurt,  zoolak,  fermilac,  etc.,  are  made 
from  sterilized  milk  by  fermentation  with  lactic  acid 
bacteria.  These  preparations  contain  neither  alcohol 
nor  carbonic  acid  gas. 

Detailed  directions  for  the  preparation  of  various 
kinds  of  fermented  milks  will  be  found  in  nurses1  cook 
books,  and  in  the  circulars  supplied  with  the  various 
lactic  acid  bacillus  cultures  on  the  market. 


CHAPTER  XXVIII 

BACTERIAL  FOOD  POISONS 

ALTHOUGH  poisoning  occasionally  results  from  mineral 
poisons  accidentally  present  in  food,  and  poisoning  may 
also  be  caused  by  fungi,  by  far  the  largest  proportion  of 
cases  of  food  poisoning  are  due  to  bacteria  which  develop 
on  animal  or  vegetable  foods.  Among  these  are  certain 
types  which  produce  powerful  toxins  analogous  to  diph- 
theria or  tetanus  toxins.  All  dead  organic  matter  offers 
an  excellent  culture-medium  for  the  growth  of  bacteria, 
and  only  careful  storing  and  thorough  cooking  will  pre- 
vent their  development  and  the  mischief  they  cause. 

The  Bacillus  enteritidis  was  found  by  Gartner  to  be 
the  cause  of  a  severe  epidemic  of  food  poisoning,  and  was 
.traced  to  meat  from  a  diseased  cow.  This  organism 
is  apparently  closely  related  to  the  common  colon 
bacillus,  a  normal  inhabitant  of  the  intestinal  tract, 
which  may,  however,  under  certain  conditions  become 
pathogenic.  Like  the  colon  bacillus,  it  forms  a  toxin 
which  resists  heating,  so  that  ordinary  boiling  does  not 
render  the  tainted  food  harmless.  There  is  nothing  in 
the  odor  or  appearance  of  the  meat  to  excite  suspicion. 

One  of  the  most  frequent  and  most  thoroughly  studied 
causes  of  epidemic  outbreaks  of  food  poisoning  is  the 
Bacillus  botulinus.  This  was  first  studied  by  Van  Er- 
mengem  in  some  30  cases,  all  of  which  were  due  to 
the  eating  of  badly  cured  ham.  The  bacillus  is  a  spore- 
bearing  anaerobe  of  slight  motility,  producing  a  powerful 

139 


140  APPLIED   BACTERIOLOGY   FOR   NURSES 

toxin  which  acts  on  the  nerve-cells,  but  which  is,  fortun- 
ately, easily  destroyed  by  heat.  The  appearance  of  the 
food  gives  no  warning,  although  there  may  be  a  slight 
rancid  odor. 

Another  organism  which  may  cause  trouble  is  the 
Bacillus  proteus  vulgaris.  This  also  does  not  alter  the 
appearance  of  the  food;  boiling  renders  its  toxin  harm- 
less. This  explains  why  botulinus  and  proteus  infections 
are  almost  entirely  caused  by  the  eating  of  sausages 
and  ham,  which  in  Northern  Europe  are  smoked,  but 
not  cooked. 

Anthrax  has  been  known  to  be  conveyed  to  man 
through  the  meat  of  calves  or  cattle  suffering  from  the 
disease,  as  well  as  through  gelatin  made  from  calves' 
feet.  As  anthrax  spores  are  very  resistant  to  heat, 
ordinary  boiling  may  not  suffice  to  kill  them. 

Fish,  as  well  as  meat,  can  be  the  carrier  of  infection. 
This  may  be  due  to  sewage  contamination  of  the  water 
(e.  g.,  oysters  spreading  typhoid  fever),  or  it  may  be  due 
to  the  development  of  poisonous  bacteria  in  smoked  or 
canned  fish. 

Milk,  as  stated  before,  is  an  excellent  culture-medium 
for  bacteria,  and  may,  consequently,  be  responsible  for 
certain  epidemics  of  poisoning.  Apart  from  such 
diseases  as  typhoid,  there  are  on  record  certain  epi- 
demics of  "milk  poisoning,"  notably  one  in  Christiania 
in  1888,  which  numbered  6000  cases  in  three  weeks. 
A  colon-like  bacillus  has  been  isolated  from  some  of  these 
epidemics.  What  applies  to  milk  is  true  also  of  the 
milk  products,  notably,  cheese  and  ice-cream;  poisoning 
by  these  is  due  to  the  presence  of  bacteria  which  belong 
to  the  colon  group. 


BACTERIAL   FOOD   POISONS  141 

From  the  foregoing  it  becomes  evident  that  careful 
inspection  of  all  food  stuffs  is  necessary,  together  with 
such  storing  and  preparation  as  will  keep  them  in  whole- 
some condition.  Where  proper  storage  facilities  exist 
(i.  e.,  large  cold-storage  plants),  in  which  edibles  are 
kept  at  a  constantly  low  temperature,  meat,  fish,  eggs, 
fruit,  etc.,  can  be  kept  in  good  condition  for  months. 
In  the  absence  of  such  facilities,  perishable  foods  must 
be  freshly  consumed.  In  warm  weather  it  is  not  safe 
to  keep  fish  for  more  than  twenty-four  hours.  In  the 
home  foods  must  be  kept  in  the  refrigerator.  While 
bacterial  growth  at  refrigerator  temperature  is  very 
slow,  it  is  not  entirely  inhibited,  and  for  this  reason  the 
ice-chest  must  be  kept  very  clean.  It  is  especially  im- 
portant that  food  spilled  on  the  shelves  be  immediately 
removed;  the  ice-box  should  be  washed  from  time  to 
time  with  a  solution  of  soda  in  hot  water  and  quickly 
cooled  again;  at  all  times  it  should  be  kept  well  filled 
with  ice.  The  fluctuations  of  temperature  due  to  insuf- 
ficient ice  supply  are  especially  harmful. 

From  what  has  been  said  elsewhere  of  the  habits  of 
the  house-fly,  it  follows  that  no  food  must  be  allowed  to 
stand  around  in  uncovered  vessels.  Food  which  is  at  all 
suspicious  as  to  color  or  odor  should  be  discarded,  and  all 
foods  which  are  not  perfectly  fresh — including  canned 
fruits  and  vegetables — should  be  thoroughly  cooked 
before  eating. 

When  bacterial  decomposition  has  taken  place  in 
canned  food  the  tops  of  the  cans  may  present  a  convex 
surface,  making  what  is  known  as  a  "blown"  can  or  a 
"swelled  head."  The  contents  of  a  "blown"  can  should, 
therefore,  never  be  used  for  food. 


CHAPTER  XXIX 

BACTERIOLOGY  OF  WATER 

ALL  waters  probably  contain  a  greater  or  lesser  num- 
ber of  bacteria,  although  those  of  the  pathogenic  variety 
are  found  only  when  there  is  direct  contamination  from 
human  sources.  The  naked-eye  appearance  of  any 
sample  of  water  is  rarely  indicative  of  its  safety;  some 
very  clear  and  sparkling  water  may  be  contaminated  with 
typhoid  bacilli  and  constitute  a  serious  menace,  while  a 
turbid  water  may  owe  its  lack  of  clearness  and  a  possible 
disagreeable  taste  and  odor  to  the  presence  of  minute 
water  plants  and  algae  that  are  absolutely  harmless. 

Pollution  to  be  Guarded  Against. — Rural  communities 
depend  almost  entirely  on  springs  and  wells  for  their 
water  supply,  and  great  care  is  necessary  to  so  locate  cess- 
pools, privies,  drains,  stable  sinks,  etc.,  that  their  dis- 
charge or  overflow  may  not  contaminate  the  drinking- 
water.  Shallow  wells,  which  are  nearer  the  surface  and 
receive  the  local  wash  after  a  rainstorm,  are  naturally 
richer  in  bacteria  than  deep  wells,  and  in  farming  regions, 
in  pasture  lands,  may  contain  large  numbers  of  intestinal 
bacteria. 

For  cities  the  supply  of  safe  and  pure  water  has  be- 
come a  very  important  and  serious  problem.  Where 
mountain  springs  are  abundant,  within  reasonable  dis- 
tance, the  water  may  be  allowed  to  collect  in  reservoirs 
and  be  conducted  to  the  city,  often  a  distance  of  many 

142 


BACTERIOLOGY    OF    WATER  143 

miles.  Such  water  is  apt  to  be  excellent,  provided  proper 
care  is  taken  to  prevent  pollution  at  the  reservoirs,  but 
for  most  large  towns  and  cities  such  a  supply  is  un- 
available, and  they  must  often  take  their  supply  from 
lakes  or  rivers.  In  these  cases  the  danger  from  pollu- 
tion is  very  great,  especially  if  the  country  around  the 
body  of  water  is  thickly  settled,  and  town  after  town 
empties  its  sewers  into  the  same.  The  water  of  some 
rivers  is  practically  dilute  sewage,  and  polluting  material 
is  added  so  fast  that  the  natural  means  of  purification 
are  entirely  unavailing. 

Natural  Purification  of  Water. — The  most  important  of 
the  natural  agents  of  purification  are  sedimentation,  oxida- 
tion, and  the  disinfecting  action  of  sunlight.  By  sedimen- 
tation the  large  foreign  bodies  suspended  in  the  water 
carry  with  them  to  the  bottom  many  bacteria,  and  other 
bacteria  are  killed  through  the  life-activities  of  certain 
water  plants.  Sunlight  does  not  act  to  any  great  depth, 
but  probably  kills  many  bacteria  in  the  water  at  the 
surface.  Freezing  mechanically  frees  water  from  a  certain 
percentage  of  impurities,  including  bacteria,  by  squeezing 
them  out,  but  low  temperatures  do  not  kill  all  germs; 
hence  the  danger  of  using  ice  from  polluted  lakes  and 
streams. 

Water-borne  Diseases. — The  two  most  important 
water-borne  diseases  are  typhoid  fever  and  Asiatic  cholera, 
and  the  latter  disease  has  furnished  a  classic  example  of 
sewage  contamination  of  drinking-water  and  its  conse- 
quences, as  well  as  the  most  striking  proof  of  the  efficiency 
of  filtration.  The  two  towns  of  Hamburg  and  Altona  are 
situated  closely  together,  at  the  mouth  of  the  river  Elbe, 
and  both  draw  upon  that  river  for  their  water  supply. 


144  APPLIED   BACTERIOLOGY    FOR   NURSES 

When,  in  1892,  the  river  water  became  polluted  with  the 
discharges  of  a  cholera  patient,  Altona,  which  used  filtered 
water,  had  but  a  few  cases,  most  of  which  could  be  traced 
to  Hamburg;  while  the  latter  city,  whose  sand-filters  were 
not  yet  completed,  paid  a  toll  of  8000  lives.  Bacterial 
examination  of  the  water  at  Albany,  N.  Y.,  has  shown 
that  the  sand-filters  in  use  there  remove  from  98  to  99 
per  cent,  of  all  the  bacteria  in  the  water.  In  Albany, 
as  in  other  cities,  the  introduction  of  filter  plants  has 
enormously  reduced  the  number  of  deaths  from  typhoid 
fever. 

Filtration  of  Water  Supplies.— Briefly,  these  filters  are 
huge  reservoirs  which  hold  a  layer  of  coarse,  broken  stone, 
upon  this  a  layer  of  smaller  stone  and  gravel,  then  a  layer 
of  coarse  sand,  and  at  the  top  one  of  fine  sand.  As  the 
dirty  water  percolates  through  these  different  layers  it 
gradually  deposits  its  gross  impurities  at  the  top,  and  coats 
the  individual  sand  grains  with  a  slimy  covering.  This 
"dirt  cover"  forms  the  really  efficient  filter,  but  it  finally 
becomes  too  tenacious  to  allow  any  water  to  pass  through, 
and  must  be  scraped  off  about  once  a  month,  hence  it  is 
necessary  always  to  have  at  least  two  filtering  beds. 
The  water  must  not  flow  through  the  filters  faster  than 
4  to  4J  inches  per  hour,  as  otherwise  infectious  material 
may  be  carried  through.  Waters  which  are  very  dirty 
require  sedimentation  to  rid  them  of  the  grossest  im- 
purities before  filtering.  When,  at  the  same  time,  the 
color  is  muddy,  it  is  often  advisable  to  add  a  chemical, 
usually  alum,  which  acts  much  as  egg-white  in  clearing 
fluids,  and  then  to  remove  the  jelly-like  aluminum  hydrate 
plus  impurities  through  a  relatively  thin  sand-filter. 

Domestic  Filters. — Household  filtration  ought  to  be  only 


BACTERIOLOGY   OF   WATER  145 

a  temporary  makeshift.  There  are  some  very  good  types 
of  domestic  filters,  but  they  are  costly,  and  require  very 
intelligent  and  conscientious  handling  to  give  good  results. 
Many  of  the  cheap  ones  are  worse  than  useless  because 
they  cannot  be  cleaned  at  all,  and  thus  soon  become  veri- 
table culture-media  for  bacteria.  This  is  true  of  sand, 
charcoal,  and  sponge  filters,  which,  after  the  first  few  days, 
are  merely  "strainers,"  keeping  back  gross  impurities, 
but  allowing  bacteria  to  grow  in  them  and  pass  out  into 
the  "filtered"  water  in  greatly  increased  numbers. 
Good  types  of  domestic  filters  are  the  Pasteur  and  the 
Berkefeld  filters.  Both  consist  of  a  cylinder  of  porous 
porcelain  called  a  "candle,"  fitted  within  a  larger  metal 
cylinder.  The  metal  cylinder  is  attached  to  the  faucet, 
the  water  enters  it  and  cannot  leave  it  except  through 
the  porcelain  candle,  which  retains  all  bacteria.  But 
there  is  danger  of  the  bacteria  "growing  through"  the 
candle;  hence  it  becomes  necessary  to  boil  and  scrub  the 
candle  every  few  days,  and  then  dry  it  in  the  oven  to 
kill  all  germs.  After  that  the  filter  is  again  efficient. 
There  must  be  a  tight  connection  between  the  two 
cylinders,  as  otherwise  unfiltered  water  may  mix  with 
the  filtered. 

Purification  by  Chlorination. — Many  cities,  New  York, 
for  example,  now  disinfect  their  water  supplies  by  means 
of  chlorin.  At  first  chlorinated  lime  was  used,  but  now 
compressed  chlorin  gas  (liquid  chlorin)  is  preferred.  This 
is  obtainable  in  steel  cylinders  similar  to  those  used  for 
liquid  carbon  dioxid.  In  disinfecting  water  supplies  y5Q 
part  of  chlorin  is  added  to  1,000,000  parts  of  water. 
While  the  water  is  not  made  sterile,  the  number  of  bac- 
teria is  greatly  reduced,  especially  the  number  of  bacilli 
10 


146  APPLIED   BACTERIOLOGY  FOR   NURSES 

of  the  colon-typhoid  type.  This  method,  therefore,  affords 
a  simple  means  of  protecting  communities  against  water- 
borne  typhoid  fever  and  other  water-borne  diseases. 

Purification  by  Distillation. — Another  method  of  puri- 
fying water  is  to  distil  it,  i.  e.,  to  convert  it  into  steam 
and  condense  the  steam  in  a  vessel  kept  cold.  Freshly 
distilled  water  is  absolutely  pure,  since  not  only  all  living 
organisms  are  destroyed,  but  any  chemicals  in  solution 
are  kept  back.  Such  water  is  quite  expensive  and  not 
particularly  palatable.  Its  continued  use  as  a  drinking- 
water  is  thought  by  some  to  be  harmful,  owing  to  the  ab- 
sence of  any  salts  and  the  likelihood  to  abstract  salt  from 
the  tissues. 

Purification  by  Boiling. — Probably  the  simplest,  easiest, 
and,  at  the  same  time,  a  very  safe  process  of  household 
purification  of  water  is  to  boil  it  for  ten  minutes.  The 
objectionable  "flat"  taste  can  be  removed,  for  drinking- 
water,  by  pouring  from  the  vessel  at  a  considerable  height, 
or  by  shaking  it  in  an  open  vessel  to  aerate  it.  Of  course, 
water  which  has  been  boiled  to  sterilize  it  for  surgical  pur- 
poses must  be  kept  in  a  properly  cotton-plugged  vessel  to 
prevent  air  contamination. 

Bacteriologic  Examination  of  Water. — Regular  bac- 
teriologic  examinations  of  the  water  supply  of  a  town 
are  made  in  order  to  keep  informed  on  the  purity  of 
the  water  and  to  enable  one  to  locate  contamination 
at  once.  If  tap-water  is  to  be  tested,  it  is  necessary 
to  allow  it  to  run  for  some  time,  so  as  to  flush  the  pipes 
and  taps.  If  an  examination  is  desired  of  lake  or  river 
water,  samples  are  taken  in  sterile  vessels  which  are 
shipped  to  the  laboratory  in  ice.  A  definite  amount 
of  water  (1  c.c.  or  less)  is  then  added  to  a  tubeful 


BACTERIOLOGY   OF   WATER  147 

of  melted  agar,  at  40°  C.,  the  mixture  is  poured  in  a 
Petri  dish  and  allowed  to  stand  at  22°  C.  for  forty-eight 
hours.  Then  the  number  of  colonies  is  counted.  Since 
the  bacterial  examination  of  water  yields  only  approxi- 
mate results,  the  American  Public  Health  Association 
has  set  up  certain  standards  that  insure  uniform  methods 
and  allow  the  results  to  be  compared. 

If  there  is  any  reason  to  suspect  sewage  contamina- 
tion, special  tests  are  made  to  isolate  the  Bacillus  coli. 
The  water  is  added  to  lactose  broth  in  a  fermentation 
tube  and  is  incubated  at  37°  C.  for  three  days.  The 
production  of  gas  in  the  closed  arm  of  the  tube  points 
to  the  presence  of  Bacillus  coli.  When  litmus  is  added 
to  lactose-agar,  and  the  suspected  sample  of  water  is 
plated  out,  the  colon  bacillus  will  produce  acid  which 
causes  its  colonies  to  be  surrounded  by  a  red  halo,  while 
the  rest  of  the  culture-medium  is  blue.  A  few  colon 
bacilli  may  accidentally  occur  in  water,  which  is  safe,  but 
their  presence  in  large  numbers  spells  danger.  It  is 
difficult  to  isolate  the  cholera  vibrio  and  especially  the 
typhoid  bacillus  from  contaminated  drinking-water, 
hence  the  presence  of  colon  bacilli  is  taken  as  showing 
sewage  contamination,  and  the  number  of  these  organ- 
isms as  the  index  of  danger. 


CHAPTER  XXX 

ANIMAL  PARASITES 

ALTHOUGH  in  no  sense  related  to  bacteria,  we  venture 
to  include  a  few  words  concerning  some  of  the  commoner 
animal  parasites  of  man,  because,  in  most  instances,  the 
methods  of  guarding  against  such  infections  is  similar 
to  those  employed  in  guarding  against  bacterial  infec- 
tion. 

Tapeworms. — These  have  a  double  cycle  of  life,  exist- 
ing in  man  as  the  common  tapeworm  familiar  to  all, 
and  in  the  flesh  of  cattle  or  hogs  in  the  form  of  tiny 
"bladder  worms."  The  common  tapeworm  of  North 
America  is  found  in  the  meat  of  cattle,  and,  while  it  is 
readily  killed  by  cooking  the  meat,  is  liable  to  infect 
persons  who  eat  raw  meat. 

Sometimes  it  happens  that  man  accidentally  takes 
into  his  stomach  the  ripe  ova  (eggs)  of  a  tapeworm. 
When  this  happens  he  is  liable  to  become  the  interme- 
diate host,  the  part  usually  played  by  the  pig  or  by 
cattle.  A  disease  known  as  "echinococcus  disease"  is 
caused  by  man  accidentally  swallowing  the  ripe  ova  of  a. 
tapeworm  ordinarily  infecting  dogs. 

Trichina. — This  is  a  parasite  found  in  the  flesh  of  hogs 
and  transmissible  to  man.  From  the  intestinal  canal  of 
man  these  tiny  worms  pass  into  the  muscles,  where  they 
lodge  and  give  rise  to  considerable  pain  and  weakness. 
Trichiniasis,  as  the  disease  is  called,  is  uncommon  in 

148 


ANIMAL  PARASITES  149 

this  country,  where  but  little  pork  is  eaten  raw.  Infec- 
tion is  usually  due  to  eating  raw  (merely  smoked)  ham. 

Hookworm. — A  disease  common  in  Porto  Rico  and  in 
the  Southern  States  is  due  to  infection  with  hookworm. 
This  parasite  appears  to  live  only  in  man,  and  infection 
usually  take's  place  through  the  skin,  especially  in  those 
walking  barefooted.  The  first  symptoms  are  those  due 
to  the  penetration  of  the  skin  by  the  young  worm,  and 
constitute  what  is  known  as  "ground  itch."  Subse- 
quently the  parasites  enter  the  intestines  and  give  rise 
to  very  characteristic  symptoms,  chief  among  which  are 
anemia  and  laziness.  The  worm  is  sometimes  spoken 
of  as  the  "lazy  worm." 

Filaria. — The  disease  known  as  "filariasis"  and  "ele- 
phantiasis" is  due  to  infection  with  a  tiny  worm  which 
invades  the  blood  and  lymph  passages.  This  infection  is 
transmitted  by  a  species  of  mosquito. 

So  far  as  the  nurse  is  concerned,  the  description  of  the 
mode  of  infection,  as  just  presented,  should  suffice  to 
indicate  the  mode  of  prevention. 


CHAPTER  XXXI 
THE  PRACTICE  OF  DISINFECTION 

Boiling  Water. — The  simplest  method  of  disinfec- 
tion, and  one  which  can  be  used  in  the  most  primi- 
tive establishments  as  well  as  in  the  best  equipped 
hospital,  is  boiling.  No  bacteria  can  withstand  the 
action  of  boiling  water  if  continued  for  a  sufficient  length 
of  time.  Most  pathogenic  bacteria  are  killed  by  boiling 


Fig.  45. — White  enameled  steel  office  sterilizer  with  handles  and  a 
perforated  tray  (Ashton). 

at  the  end  of  ten  minutes,  while  spore-bearers,  like  the 
anthrax  bacillus,  may  require  a  half -hour  or  even  longer. 
Any  vessel  which  can  be  covered  and  placed  over  a  fire 
answers  for  a  sterilizer,  though,  of  course,  there  are 
many  types  on  the  market  constructed  to  suit  various 
purposes.  Usually  they  consist  of  a  covered  pan,  fitted 

150 


THE   PRACTICE   OF  DISINFECTION  151 

with  a  perforated  tray  or  wire  basket,  supplied  with 
handles,  to  enable  one  to  lift  the  sterilized  instruments, 
etc.,  out  of  the  boiling  water.  The  addition  of  2  per 
cent,  of  ordinary  washing  soda  to  the  water  increases  its 
disinfecting  action,  and  at  the  same  time  prevents  in  a 
measure  the  rusting  of  metal  instruments. 

This  method  of  sterilization  is  particularly  well 
suited  for  soiled  linens,  for  dishes,  trays,  pans,  etc., 
that  have  come  in  contact  with  infectious  material,  for 
glass  and  metal  instruments,  such  as  catheters,  irriga- 
tion tubes,  forceps,  etc.  It  is  not  so  well  suited  for  the 
sterilization  of  knives  and  scissors,  since  it  spoils  their 
keen  cutting  edge.  For  this  reason  some  surgeons  pre- 
fer to  have  these  instruments  kept  in  pure  carbolic  acid 
and  transferred  to  sterile  water  before  the  operation. 
Catheters  are  to  advantage  boiled  in  water  to  which 
have  been  added  2  teaspoonfuls  of  liquid  vaselin.  This 
forms  a  thin,  even  coating  of  a  sterile  lubricant  over  the 
entire  surface.  Soiled  linen  should  not  at  once  be  put 
into  boiling  water,  since  this  fixes  any  stains;  it  may  be 
put  to  soak  for  a  few  hours  in  cold  water  containing  a 
pound  of  green  soap  in  25  gallons,  and  then  may  be 
heated  in  this  to  70°  or  80°  C.  These  suds  are  then 
allowed  to  run  off  and  are  replaced  by  fresh,  in  which 
the  linen  is  boiled  fifteen  to  twenty  minutes. 

Steam. — A  second  method  of  using  moist  heat  is  in 
the  form  of  live  steam  in  a  steam  sterilizer,  of  which  the 
Arnold  sterilizer,  already  described,  is  a  good  example. 
This  type  of  sterilizer  is  extensively  used  in  bacteriologic 
laboratories  for  the  sterilization  of  culture-media,  and 
in  hospitals  for  sterilizing  dressings,  rubber  gloves,  etc. 
Heating  to  212°  F.  (100°  C.)  for  an  hour  is  enough  to 


152  APPLIED    BACTERIOLOGY   FOR   NURSES 

destroy  all  disease  germs.  Some  culture-media,  when 
heated  to  that  degree  for  so  long  a  time,  undergo  un- 
desirable chemic  changes;  such  media  are  subjected 
to  what  is  known  as  fractional  sterilization.  They  are 
heated  in  the  Arnold  sterilizer  for  twenty  minutes  on 
three  consecutive  days;  the  first  heating  destroys  most, 


Fig.  46. — Arnold's  steam  sterilizer  (Boston  Board  of  Health  form). 

if  not  all,  of  the  vegetating  bacteria,  and  in  the  interval 
between  the  first  and  second  heating  the  spores  possibly 
present  will  develop  into  vegetative  bacteria,  in  which 
state  they  are  easily  killed  by  the  second  heating.  The 
process  is  repeated  on  the  third  day,  in  order  to  insure 
the  death  of  all  organisms  which  may  have  escaped  the 
first  two  heatings. 


THE   PRACTICE    OF  DISINFECTION  153 

Steam  Under  Pressure. — When  water  is  heated  in 
an  open  vessel  or  one  loosely  covered — that  is,  at  at- 
mospheric pressure — the  temperature  cannot  go  above 


Fig.  47. — Autoclave  sterilizer.  Except  in  form,  the  autoclave  differs 
but  slightly  from  the  full-jacketed  sterilizer  (Fig.  22,  page  46). 
It  is  made  of  heavy  copper  with  solid  cast  brass  self-sealing  door; 
the  safety-valve  is  set  to  relieve  at  15  pounds,  and  the  jacket  extends 
entirely  around  the  chamber.  The  pressure,  however,  cannot  be 
retained  in  the  jacket  while  the  door  is  open.  Surgical  dressings 
when  withdrawn  from  the  autoclave  are  dry.  The  latent  heat  of 
the  steam  at  the  high  pressure  will  evaporate  any  moisture  from  the 
steam  instantly  upon  exposure  to  the  atmosphere. 

212°  F.  (100°  C.),  but  when  heated  in  a  tightly  closed 
container  both  the  temperature  and  pressure  increase, 
so  that  a  temperature  of  130°  C.  and  more,  according 
to  the  amount  of  pressure  employed,  may  be  reached. 


154 


APPLIED   BACTERIOLOGY   FOR    NURSES 


Under  these  conditions  the  steam  generated  not  only 
kills  bacteria  more  readily  than  steam  generated  at 
atmospheric  pressure,  but  also  has  a  much  greater 
power  to  penetrate  to  the  interior  of  bulky  objects,  such 
as  mattresses,  bundles  of  dressings,  or  clothing.  Steam 
under  pressure  is,  therefore,  a  more  valuable  disinfect- 
ant. A  good  example  of  high-pressure  steam  sterilizer 
is  shown  in  Fig.  47. 


Fig.  48. — Diagram  showing  construction  of  a  pressure  steam 
sterilizer. 

Another  excellent  type  of  pressure  steam  sterilizer 
consists  of  an  outer  and  an  inner  jacket  made  of  sheet 
metal.  The  space  between  these  two,  A,  is  half-filled 
with  water,  which  is  heated  either  from  below  by  a 
gas  burner  or  by  means  of  steam  circulating  in  coils  ((7) 
within.  As  the  water  grows  hotter,  the  air  in  the  dis- 
infecting chamber,  J5,  becomes  rarefied,  and  may  be 


THE   PRACTICE   OF  DISINFECTION  155 

further  exhausted  by  means  of  an  exhaust  valve  (D). 
When  a  partial  vacuum  has  been  created  (5  inches,  as 
registered  by  the  gauge)  the  exhaust  valve  is  shut  off, 
and  through  another  valve  (E)  steam  from  the  steam 
chamber  is  admitted.  As  this  steam  finds  a  partial 
vacuum  it  eagerly  penetrates  any  pervious  material 
placed  in  the  sterilizing  chamber.  Dressings  and  all 
material  to  be  sterilized  are  put  into  the  apparatus  as 
soon  as  the  heating  is  started,  and  are,  therefore,  gradu- 
ally warmed;  consequently,  when  steam  is  admitted, 
it  does  not  condense  and  does  not  wet  the  dressings. 
When  the  dressings,  etc.,  have  been  in  contact  with  the 
steam  (the  temperature  of  which  varies  according  to  the 
pressure  under  which  it  is  produced)  for  twenty  to 
thirty  minutes  the  exhaust  valve  is  again  operated,  for 
the  purpose  of  sucking  the  excess  of  steam  out  of  the 
material  and  leaving  it  very  nearly  dry. 

When  the  door  of  the  apparatus  is  to  be  opened,  the 
vacuum  must  first  be  destroyed  by  admitting  air  into 
the  steam  chamber  through  another  valve  (F),  which  is 
plugged  with  cotton. 

The  large  municipal  or  private  steam  disinfecting 
plants  act  on  the  same  principle,  and  differ  only  in  size 
and  details  of  construction. 

This  method  of  disinfection  can  be  used  for  all  ordi- 
nary cotton  and  woolen  garments,  bedding,  rugs,  mail 
from  infected  ports,  etc.,  but  it  is  not  suited  to  rubber 
articles,  furs,  leather,  delicate  silks,  or  articles  manu- 
factured with  glue,  such  as  books.  Experiments  con- 
ducted at  the  New  York  Quarantine  Disinfecting  Station 
with  self-registering  thermometers  have  shown  that 
when  a  temperature  of  110°  F.  is  maintained  in  the  dis- 


156 


APPLIED   BACTERIOLOGY   FOR   NURSES 


infecting  chamber  for  fifteen  minutes,  the  same,  or  but 
a  slightly  lower  temperature,  is  reached  in  the  center 
of  large  bundles  of  clothes  and  bedding. 


Fig.  49. — Autoclave  (horizontal  form). 

Dry  Heat.— When   the   rapid   sterilization  of  small 
instruments,  such  as  hypodermic  needles,  glass  rods, 


THE   PRACTICE  OF  DISINFECTION  157 

etc.,  is  required,  these  articles  may  be  passed  through 
the  flame.  This  is  the  regular  method  of  sterilizing  the 
platinum  wire  used  to  transfer  bacteria.  But,  except  in 
an  emergency,  this  method  should  not  be  used  for 
surgical  instruments,  as  it  destroys  the  temper  of  steel 
and  ruins  the  cutting  edge  of  knives. 

Glassware,  such  as  catheters,  pipets,  test-tubes,  etc., 
is  sterilized  in  a  hot-air  oven.  This  is  a  box  made  of 
sheet  metal  with  double  walls,  between  which  the  hot 
air  circulates.  It  is  heated  by  gas  burners  from  below, 
and  a  temperature  of  150°  C.  for  one  hour  is  required 
to  properly  sterilize  the  glass-  or  metal-ware,  for  which 
alone  it  should  be  used.  The  oven  of  an  ordinary  kitchen 
range  answers  very  well  for  a  substitute.  (See  Fig.  19, 
p.  43.) 

Chemicals. — There  are  a  few  objects  which  cannot 
be  sterilized  by  any  of  the  foregoing  methods.  Men- 
tion has  already  been  made  of  the  fact  that  boiling 
dulls  the  edge  of  knives,  which  are,  therefore,  kept  in 
pure  carbolic.  Clinical  thermometers  are  also  kept  in  a 
carbolic  solution.  One  of  the  most  difficult  materials 
to  render  and  to  keep  sterile  is  catgut,  and  several  ways 
have  been  devised  for  its  sterilization.  Catgut  may  be 
sterilized  by  dry  heat,  being  first  heated  to  70°  C.  for 
two  hours,  to  drive  off  the  moisture.  When  this  has 
been  accomplished  the  catgut  may  be  exposed  to  a 
temperature  of  150°  C.  without  becoming  brittle.  To 
keep  it  sterile  it  is  stored  in  tubes  plugged  with  cotton. 
When  there  is  any  doubt  about  its  sterility  it  may  be 
placed  for  eight  days  in  a  3  per  cent,  solution  of  iodin 
in  acetone,  then  into  acetone  for  four  days,  to  remove  the 
excess  of  iodin,  and,  finally,  into  a  mixture  of  acetone 


158  APPLIED   BACTERIOLOGY  FOR   NURSES 

85  parts,  Columbia  spirits   10  parts,  glycerin  5  parts. 
In  this  mixture  it  is  kept  until  used. 

Preparation  of  Patient  for  Operation.— Until  com- 
paratively recently  it  was  the  practice  to  prepare  the 
patient  for  an  operation  by  a  full  bath  on  the  preceding 
night,  to  shave  the  site  of  the  operation,  and  carefully 
cleanse  it  with  hot  water  and  green  soap.  It  was  then 
rinsed  with  alcohol  and  ether  and  with  a  1: 1000  solution 
of  bichlorid  of  mercury.  Then  a  gauze  compress  was 
applied  which  had  been  soaked  in  a  25  per  cent,  solution 
of  green  soap  in  water;  this  was  covered  with  rubber 
tissue,  and  left  in  place  from  three  to  twelve  hours. 
The  washing  with  alcohol,  ether,  and  bichlorid  was  then 
repeated  and  the  skin  covered  with  a  bichlorid  bandage. 
Just  before  the  operation  it  was  again  scrubbed  with 
soap  and  washed  with  alcohol  and  ether  and  bichlorid. 
This  method  was  fairly  efficient  to  sterilize  the  patient's 
skin,  but  it  was  cumbersome  and  very  uncomfortable 
to  the  patient.  Moreover,  it  was  found  that  an  absolute 
disinfection  of  the  living  skin  could  not  be  hoped  for  by 
any  amount  of  scrubbing,  since  the  deep  skin  glands 
continued  to  harbor  bacteria.  Some  surgeons  then 
covered  the  skin  with  an  aseptic,  gum-like  substance, 
with  the  intention  of  holding  the  inevitable  skin  bac- 
teria in  place.  These  substances  were  apt  to  crack  or 
tear  and  were  not  extensively  used.  Alcohol  has  a  hard- 
ening effect  on  the  skin,  and  tends  to  "fix"  the  bacteria 
there;  it  is  used  either  alone  or  as  a  strong  tincture  of 
green  soap  as  the  sole  disinfectant  by  some  operators. 
This  action  is  transient,  and  may  be  increased  by  adding 
to  the  alcohol  such  substances  as  tannin,  ether,  or  nitric 
acid.  A  method  which  has  found  much  favor  both  here 


THE   PRACTICE   OF  DISINFECTION  159 

and  abroad  is  the  disinfection  by  iodin.  The  patient 
receives  a  full  bath  on  the  evening  preceding  the  opera- 
tion; any  hairy  portions  of  the  skin  are  shaved,  but  no 
dressing  whatever  is  used;  just  before  anesthetizing  the 
site  of  the  operation  is  painted  with  a  solution  of  iodin 
in  50  per  cent,  alcohol  and  is  covered  with  sterile  towels. 
The  painting  is  repeated  just  before  the  operation. 
The  action  of  the  iodin  is  the  same  as  that  of  alcohol, 
but  is  more  pronounced  and  lasting.  Its  greatest  dis- 
advantage is  the  occasional  development  of  an  iodin 
dermatitis;  this  is  most  likely  to  occur  when  the  solu- 
tion used  is  too  strong  (it  should  not  be  more  than  5 
per  cent.);  second,  when  the  solution  is  old  and  con- 
tains decomposition  products  of  iodin;  third,  when  the 
skin  is  unusually  tender,  as  in  children;  or,  fourth,  when 
the  skin  has  been  previously  washed  with  antiseptic 
solutions  or  even  plain  water.  In  emergency  cases  no 
previous  washing  is  resorted  to,  but  the  skin  is  cleaned 
with  a  1  per  cent,  solution  of  iodin  in  benzene  two  to 
five  minutes  before  the  iodin  is  applied. 

Disinfection  of  the  hands  is  closely  allied  with  the 
preparation  of  the  patient,  and,  to  a  certain  extent, 
the  same  methods  can  be  used  for  both.  A  ten  minutes' 
scrubbing  with  a  bristle  brush,  using  hot  water  and  a 
tincture  of  green  soap,  and  giving  special  attention  to 
the  skin  folds  at  the  base  of  the  nails  and  the  space 
under  the  nails,  is  followed  by  rinsing  in  alcohol,  ether^ 
and  bichlorid  solution.  Hands  may  thus  be  superficially 
sterilized,  but  when  they  are  immersed  in  hot  solutions, 
which  induces  sweating,  countless  bacteria  will  be 
driven  from  the  sweat  and  sebaceous  glands  to  the 
sterilized  surface.  This  has  been  repeatedly  proved  by 


160  APPLIED    BACTERIOLOGY   FOR   NURSES 

experiments,  and  surgeons  have  had  recourse  to  a  mild 
process  of  tanning;  that  is,  immersing  the  hands  in  a 
hardening  solution,  such  as  60  per  cent,  alcohol  or  tinc- 
ture of  iodin.  Both  of  these  substances,  when  con- 
tinuously used,  are  injurious  to  the  skin,  and  the  great 
majority  of  operators  prefer  to  wear  gloves  during 
operations  and  require  the  same  of  the  assistants. 
When  rubber  gloves  are  worn  the  soaking  of  the  hands 
in  bichlorid  solution  before  putting  on  the  gloves  may 
cause  a  severe  dermatitis.  Rubber  gloves  are  more 
frequently  used  than  those  of  lisle,  their  chief  advantages 
being  that  they  are  not  porous,  do  not  appreciably 
impair  the  tactile  sense,  and  in  certain  cases,  as  in 
exploring  a  cavity,  their  slippery  condition  is  a  material 
aid.  Against  these  are  to  be  weighed  their  greater 
initial  cost  and  their  slight  durability.  Rubber  gloves 
can  be  sterilized  in  the  same  sterilizer  in  which  instru- 
ments are  boiled,  but  they  should  be  wrapped  in  gauze 
to  prevent  their  coming  into  contact  with  metal;  or, 
they  may  be  kept  for  an  hour  in  the  Arnold  steam 
sterilizer. 

Disinfection  to  Prevent  the  Spread  of  Contagious  Dis- 
eases.— It  is  usually  far  more  important  to  prevent 
the  spread  of  contagion  during  the  patient's  illness  than 
it  is  to  fumigate  the  apartment  and  its  contents  after 
convalescence.  The  sick  room  should  be  kept  free  of 
all  unnecessary  furniture,  and  particularly  of  rugs  and 
hangings.  In  place  of  sweeping  and  dusting,  the  furni- 
ture, as  well  as  the  floor  and  any  woodwork,  should 
be  wiped  with  an  oiled  rag  or  with  a  cloth  moistened  with 
1:2000  bichlorid  solution.  No  steaming,  spraying,  or 
fumigation  of  any  efficiency  can  be  carried  out  in  an 


THE  PRACTICE   OF  DISINFECTION  161 

apartment  which  is  occupied.1  Hence,  during  the  illness, 
aside  from  thorough  ventilation,  and  the  precautions 
already  described,  the  important  thing  is  to  destroy  or 
render  harmless  any  discharges  or  dressings,  etc.,  from 
the  patient.  Anything  of  no  value,  as  dressings,  should 
be  burnt  immediately;  likewise  nasal  discharges  or  spu- 
tum collected  in  rags  or  paper  receptacles. 

Stools  of  patients  suffering  from  typhoid  fever, 
cholera,  or  other  intestinal  diseases  must  be  received 
in  covered  vessels,  and  at  once  mixed  with  a  disinfectant 
fluid;  neither  carbolic  nor  bichlorid  is  well  suited  to  the 
purpose,  since  both  are  relatively  inert  in  the  presence 
of  much  albuminous  matter.  When  chlorid  of  lime  or 
milk  of  lime  are  used,  a  good  mixture  must  be  effected  by 
thorough  stirring.  At  least  1  quart  of  the  standard 
solution  of  chlorid  of  lime  (4  ounces  to  1  gallon  of  water) 
should  be  used  for  each  dejection.  At  the  recent  Inter- 
national Congress  of  Hygiene  and  Demography,  Praus- 
nitz  advocated  Kaiser's  method  of  disinfecting  stools 
by  means  of  the  heat  generated  by  pouring  water  over 
quicklime  which  had  previously  been  mixed  with  the 
stool. 

Linen  and  cotton  clothing  is  best  boiled,  and  a  method 
has  already  been  indicated  for  its  disinfection  by  this 
process.  It  may  also  be  soaked  in  a  1 : 1000  solution  of 
bichlorid  of  mercury  or  a  1 : 50  solution  of  carbolic  acid; 
woolen  clothing,  which  would  be  injured  by  boiling, 
may  be  similarly  disinfected,  or  by  means  of  formalde- 
hyd.  All  bundles  of  infected  clothing  removed  from 

1  In  very  chronic  infectious  diseases,  like  pulmonary  tuberculosis, 
it  is,  however,  advisable  to  thoroughly  clean  and  disinfect  the 
patient's  apartment  from  time  to  time. 
11 


162  APPLIED   BACTERIOLOGY   FOR  NURSES 

the  sick  room  must  be  wrapped  in  a  sheet,  either  steril- 
ized or  wrung  from  an  antiseptic  solution,  to  prevent 
spreading  contagion  on  the  way. 

The  patient's  eating  utensils  must  not  be  used  by 
anyone  else  unless  they  have  first  been  thoroughly 
boiled.  This  is  especially  true  in  cases  of  diphtheria 
or  tuberculosis,  but  ought  to  be  applied  in  all  infectious 
diseases.  All  left-over  food  is  to  be  burned. 

After  convalescence  is  established  the  patient  should 
receive  at  least  one  full  bath  and  have  a  complete 
change  of  clothing  before  he  is  allowed  to  mingle  with 
others.  Bichlorid  of  mercury  may  or  may  not  be 
added  to  the  bath. 

Among  the  various  agents  used  to  fumigate  apart- 
ments after  an  infectious  disease  sulphur  dioxid  has  been 
extensively  used  in  the  past,  but  its  action  is  not  depend- 
able, and  it  has  been  almost  entirely  superseded  .by  for- 
maldehyd.  Sulphur  fumigation  is,  however,  still  most 
useful  in  killing  vermin,  such  as  rats  and  mice,  fleas,  lice, 
etc.  Before  fumigation  the  apartment  may  be  cleaned, 
all  gross  infectious  material — e.  g.,  dried  sputum,  etc. — 
is  soaked  in  5  per  cent,  solution  of  bichlorid  of  mercury, 
scraped  off,  and  burnt.  All  dust  is  soaked  with  the  same 
solution,  the  floors  and  all  the  wood  work  are  carefully 
washed  with  it;  also  the  walls,  if  this  is  practicable. 
Then  soap  and  hot  water  are  liberally  applied,  and  the 
apartment  is  thoroughly  ventilated.  If  this  process  is 
carefully  and  faithfully  carried  out  it  may  be  possible 
to  dispense  with  formalin  disinfection;  the  latter  is, 
however,  an  additional  safeguard.  Before  starting 
fumigation,  all  cracks  and  crevices,  keyholes,  and  other 
small  openings  are  tightly  sealed  with  gummed  paper. 


THE    PRACTICE    OF  DISINFECTION  163 

There  are  various  methods  of  generating  formaldehyd 
gas,  and  a  number  of  lamps  have  been  constructed  for 
the  purpose.  Of  late  good  results  have  been  reported  by 
mixing  the  solid  commercial  formalin  or  paraform  with 
potassium  permanganate,  using  6  ounces  of  each  for 
1000  cubic  feet  of  air  space. 

A  special  apparatus  has  been  constructed  for  this,  but 
it  is  possible  to  carry  it  out  by  using  a  deep  enameled 
pail.  The  formalin  or  paraform  must  be  thoroughly 
broken  up  before  the  permanganate  and  water  are 
added,  otherwise  much  will  remain  unaltered  and  will 
not  be  converted  into  gas.  The  fumes  are  kept  in  the 
room  for  twelve  hours,  and  when  the  process  of  disinfec- 
tion is  completed  they  may  be  displaced  by  ammonia. 
Formaldehyd  does  not  injure  wool  or  silk,  gilt,  copper, 
or  leather. 

Formaldehyd  is  a  very  efficient  surface  disinfectant, 
but  under  ordinary  circumstances  it  does  not  pene- 
trate to  any  depths.  The  "Japanese  method"  secures 
much  greater  penetration.  In  this  the  formaldehyd  gas 
is  diffused,  by  means  of  a  rather  complex  apparatus, 
throughout  steel  chambers  which  have  previously 
been  heated  to  65°  C.  Clothing,  rugs,  etc.,  are  exposed 
to  these  formaldehyd  vapors  for  fifteen  minutes  with 
satisfactory  results — i.  e.,  bacteria  in  the  interior  of  the 
bundles  were  destroyed. 

So  far  as  the  need  of  fumigation  is  concerned,  the  reader 
is  referred  to  page  56. 

The  use  of  chlorin  in  the  disinfection  of  water  supplies 
has  already  been  described.  (See  pages  39  and  145.) 

Fumigation  is  still  highly  important  to  kill  vermin.  An 
ingenious  apparatus  for  thus  disinfecting  railway  coaches 


164 


APPLIED    BACTERIOLOGY   FOR    NURSES 


is  shown  in  the  picture  here  reproduced  by  courtesy 
Popular  Science  Monthly. 


of 


1 1 

II 

51 
n 

-^ 


CWfi 

If! 

fl)      t-»      ^ 

£  IS 

«  §•§ 

2     »H   02 


S   fin 


1 1 


-C 


"S 


H?& 


V     ,      § 


.. 


CHAPTER  XXXII 

COLLECTION  OF  MATERIAL  FOR  BACTERIOLOGIC 
EXAMINATION 

OFTENTIMES  the  material  sent  to  the  laboratory  for 
bacteriologic  examination  has  been  so  improperly  col- 
lected of  handled  that  its  examination  is  entirely  use- 
less. Much  of  the  trouble  can  be  avoided  by  a  little 
attention  to  details. 

In  most  cases  bacteriologic  specimens  should  be 
collected  in  sterile  containers.  An  exception  may  be 
made  in  the  case  of  sputum  to  be  examined  micro- 
scopically for  tubercle  bacilli.  When  cultures  are  to 
be  made  the  specimens  should  be  hurried  to  the  labora- 
tory without  delay.  All  specimens  should  be  accom- 
panied by  a  memorandum  showing  the  character  and 
source  of  the  material,  the  name  of  the  patient,  date  and 
hour  of  collection,  and  a  definite  statement  as  to  what 
information  is  wanted  from  the  bacteriologist.  It  is 
important  not  to  add  disinfectants  to  specimens  from 
which  cultures  are  desired. 

Sputum.— Care  should  be  taken  that  the  specimen  of 
sputum  has  actually  been  coughed  up.  Some  patients 
will  hawk  up  mucus  coming  from  the  nose,  others  will 
spit  out  saliva,  still  others  will  be  at  a  loss  what  to  do. 
Sputum  should  never  be  sent  to  the  laboratory  merely 
in  a  gauze  handkerchief  or  on  a  piece  of  paper,  but 
only  in  a  small,  wide-mouthed  bottle  securely  corked, 

165 


166  APPLIED    BACTERIOLOGY   FOR   NURSES 

or  in  specially  prepared  water-proofed  wood  boxes. 
In  infants  and  children  sputum  can  be  obtained  by 
means  of  a  small  piece  of  gauze,  held  with  a  stick  or 
thumb  forceps  in  the  child's  throat.  This  induces  a 
reflex  cough,  with  the  expulsion  of  some  of  the  desired 
sputum  on  the  gauze. 

Throat  Smears. — When  the  throat  is  covered  with 
membrane  the  physician  often  desires  cultures  to  deter- 
mine the  nature  of  the  infection.  These  are  made  as 
follows:  Prepare  a  small  sterile  cotton  swab,  place  the 
patient  in  a  good  light,  and  then  gently  wipe  off  some  of 
the  exudate.  Make  sure  that  no  antiseptic  has  been 
applied  to  the  throat  within  the  previous  two  hours. 
If  culture-tubes  are  available,  wipe  the  swab  holding  the 
exudate  over  the  surface  of  the  culture,  being  careful 
not  to  break  the  surface.  For  accurate  diagnosis  it  is 
advisable  also  to  spread  some  of  the  exudate  on  the 
swab  on  a  glass  slide  and  send  this  along  with  the  culture. 

Water. — Water  for  bacteriologic  examination  should 
be  collected  in  sterile  1 -ounce  bottles,  and  kept  cool 
during  transportation  to  the  laboratory.  In  collecting 
water  from  a  faucet  care  should  be  taken  to  secure  a 
typic  specimen  by  allowing  the  water  to  run  for  some 
time  before  collecting.  In  the  case  of  springs,  wells, 
reservoirs,  etc.,  one  should  not  dip  water  from  the 
surface,  for  such  a  specimen  would  probably  contain  an 
undue  proportion  of  bacteria  from  the  dust  of  the  air. 

Milk. — When  milk  is  to  be  examined,  one  must  be  sure 
to  secure  a  representative  sample  by  thoroughly  mixing 
milk  and  cream.  The  latter  always  contains  a  very 
large  number  of  bacteria. 

Autopsies. — Specimens  of  organs  are  secured  free  from 


MATERIAL   FOR   BACTERIOLOGIC   EXAMINATION      167 

outside  contamination  by  first  searing  the  surface  of  the 
organ  with  a  hot  iron,  and  then  cutting  a  piece  of  tissue 
from  beneath  the  seared  surface.  Similarly,  in  secur- 
ing specimens  of  heart's  blood  the  surface  of  the  heart  is 
first  seared  with  a  hot  iron,  and  then,  with  a  sterile  hollow 
needle,  blood  is  drawn  from  witfiin  the  heart  cavity  by 
thrusting  the  needle  through  the  seared  surface.  The 
piece  of  tissue  or  blood  should  be  placed  in  a  sterile 
bottle  or  test-tube  plugged  with  cotton  and  at  once 
carried  to  the  laboratory. 

Urine. — The  nurse  will  be  familiar  with  the  collection  of 
specimens  of  urine  for  the  ordinary  chemical  and  micro- 
scopic examination.  In  certain  instances,  however,  it  is 
desired  to  make  cultures,  and  then  great  care  must  be 
taken  to  collect  the  specimens,  by  means  of  a  sterile  cath- 
eter, in  a  sterile  bottle. 

Feces. — Bacteriologic  examinations  of  feces  are  fre- 
quently undertaken  in  order  to  discover  the  presence  of 
typhoid  bacilli.  Such  specimens  should  be  placed  in  a 
clean  wide-mouthed  bottle  and  tightly  corked.  The 
bottle  should  never  be  more  than  half-full.  The  specimen 
should  be  fresh,  and  should  be  sent  to  the  laboratory 
without  delay.  In  summer  the  specimen  should  be  kept 
cool  with  ice.  Under  no  circumstances  should  a  disin- 
fectant be  added. 


CHAPTER  XXXIII 
OTHER  IMPORTANT  PATHOGENIC  MICRO-ORGANISMS 

IN  addition  to  the  micro-organisms  already  described, 
the  following  are  important  ones  pathogenic  for  man: 

Colon  Bacillus. — A  rather  plump,  Gram-negative 
bacillus,  normally  occupying  the  intestines  of  man  and 
animals,  and  capable  of  producing  infection  in  man. 


te^lt  *  *2  JV> *  &LfrvJ 


Fig.  51. — Colon  bacillus;    twenty-four-hour  agar  culture;   X  650 

(Heim). 

Occasionally  this  organism  produces  infection  in  man, 
the  commonest  form  being  pyelitis  (inflammation  of  the 
funnel-shaped  urinary  tube  connecting  the  kidney  with 
the  ureter)  and  cystitis. 

The  presence  of  colon  bacilli  is  used  in  sanitary  water 
examinations  as  an  indication  of  fecal  pollution.  Pro- 

168 


OTHER  IMPORTANT  PATHOGENIC  MICRO-ORGANISMS      169 

phylaxis   is   similar   to   that   discussed   under   Typhoid 
Bacillus. 

Pneumobacillus  of  Friedlander. — A  short  bacillus, 
often  occurring  in  pairs  or  chains  of  four,  capsulated, 
and  Gram-negative.  Found  in  certain  cases  of  pneu- 
monia and  pleurisy.  Prophylaxis  is  similar  to  that  dis- 
cussed under  the  Pneumococcus. 


Fig.   52.— Friedlander's  pneumobacillus.      Welch's  capsule   stain; 
X  1100  (Jordan). 

Paratyphoid  Bacilli. — Similar  to  typhoid  bacilli  and 
colon  bacilli,  and  producing  infections  in  man  resembling 
typhoid  fever  or,  at  times,  symptoms  of  epidemic  meat- 
poisoning.  Prophylaxis  is  discussed  under  Typhoid 
Bacillus  and  under  Bacterial  Food  Poisoning. 

Influenza  Bacillus  (Grip  Bacillus). — A  very  small, 
moderately  thick  bacillus,  growing  only  on  media  contain- 
ing blood  (hence  spoken  of  as  a  "hemophilic"  bacillus)  and 
occurring  chiefly  in  inflammations  of  the  respiratory  pass- 
ages. Experience  has  shown  that  a  large  proportion  of 
cases  called  "influenza"  or  "grip"  by  the  clinicians  are 


170  APPLIED    BACTERIOLOGY   FOR   NURSES 

really  infections  due  to  pneumococci,  streptococci,  or  other 
bacteria.  On  the  other  hand,  influenza  bacilli  are  some- 
times found  in  large  numbers  in  cases  in  which  influenza  is 
not  diagnosed.  The  extensive  country-wide  outbreak  in 
the  United  States  (December,  1915,  and  January  and  Feb- 
ruary, 1916)  appears  to  have  been  due  largely  to  strepto- 


Fig.  53.— Bacillus  of  influenza;  X  1000  (Krai). 

coccus  infection,  although  the  influenza  bacillus  played  a 
not  unimportant  role. 

Now  and  then  the  influenza  bacillus  produces  a  typical 
meningitis.  This  is  very  fatal.  A  bacillus  similar  to  the 
influenza  bacillus  appears  to  be  associated  with  whooping- 
cough.  Prophylaxis  in  influenza  is  similar  to  that  dis- 
cussed under  Pneumococcus. 

Micrococcus  of  Malta  Fever. — A  very  small,  rounded 
or  slightly  oval  micro-organism,  Gram-negative,  and 
growing  rather  feebly  on  artificial  media.  The  organ- 
ism appears  to  be  present  in  the  feces  of  goats  in  Malta, 
and  probably  contaminates  the  milk.  In  man  a  typhoid- 


OTHER  IMPORTANT  PATHOGENIC  MICRO-ORGANISMS      171 

like  fever  is  produced.    Prophylaxis  is  similar  to  that 
discussed  under  Typhoid  Bacillus. 


Fig.  54.— Micrococcus  of  Malta  fever.     Carbol  fuchsin;  X  1200 

(Jordan) . 


Fig.  55. — Bacillus  pyocyaneus.     Pure  culture  on  agar.     Fuchsin 
stain  (Kolle  and  Wassermann). 

Bacillus  Pyocyaneus. — A  slender,  aerobic,  motile  bacil- 
lus, widely  distributed  in  nature  and  occasionally  pro- 


172 


APPLIED    BACTERIOLOGY    FOR   NURSES 


ducing  infections  in  man.  These  are  characterized  by 
the  production  of  a  blue  or  blue-green  pus,  whence  the 
name,  pyocyaneus,  signifying  blue  pus.  Prophylaxis 
is  similar  to  that  described  under  Streptococcus  and 
Staphylococcus. 

Glanders  Bacillus. — A  small  bacillus  with  rounded  ends, 
Gram-negative,  non-motile.  Common  in  horses,  where 
it  produces  the  disease  known  as  glanders  or  farcy,  and 
easily  communicated  to  man,  where  it  produces  an  in- 


7-^-'  j'3  ;t-' 


Fig.  56. — Bacillus  mallei  (glanders).     Pure  culture  from  glucose- 
agar.     Carbol  fuchsin;  X  1200  (Jordan). 

fection  which  is  fatal  in  60  per  cent,  of  the  cases.  The 
infective  material  exists  in  the  secretions  of  the  horses' 
nose,  in  the  pus  of  glanders  nodules,  and  frequently  in 
the  blood.  Prophylaxis  is  indicated  by  what  has  just 
been  said.  Glandered  horses  should  be  promptly  de- 
stroyed. 


OTHER  IMPORTANT  PATHOGENIC  MICRO-ORGANISMS      173 

In  diagnosing  the  infection  in  horses  serum  examina- 
tions are  of  service.  The  serum  is  tested  by  means  of 
complement  fixation  and  agglutination  reactions.  The 
animals  can  also  be  tested  by  means  of  "mallein"  (made 
from  glanders  bacilli),  the  injection  of  mallein  being  fol- 
lowed by  a  typical  febrile  reaction. 

Bubonic  Plague  Bacillus. — Short,  thick  rods  with 
rounded  ends,  Gram-negative,  aerobic,  and  non-motile. 


Fig.  57. — Bacillus  pestis  (bubonic  plague)  in  smear  from  rat's  liver, 
showing  bipolar  staining;  X  720  (Wherry). 

In  man  the  infection  occurs  in  two  forms:  the  bubonic, 
involving  the  lymph-glands;  the  pneumonic,  involv- 
ing the  lungs.  The  disease  is  spread  directly  from  man 
to  man,  especially  in  the  pneumonic  form,  and  also 
from  rats,  ground  squirrels,  and  other  rodents  to  man. 
In  the  latter  case  infection  is  usually  intermediate  through 


174  APPLIED    BACTERIOLOGY   FOR   NURSES 

fleas  infesting  these  rodents.  Prophylaxis:  Discovery  and 
destruction  of  all  infected  rodents,  and  in  the  pneumonic 
form  extreme  care  to  guard  against  infection  through 
coughing,  sneezing,  etc.,  and  infection  from  the  sputum. 
Anthrax  Bacillus. — Mostly  in  the  form  of  slender,  non- 
motile  rods,  Gram-positive,  and  forming  spores  possess- 
ing great  resistance  to  destructive  agents.  Anthrax 
is  primarily  a  disease  of  cattle  and  sheep,  but  humans, 


Fig.  58. — Bacillus  of  anthrax  in  spleen  pulp.   Fuchsin  stain;  X  2000; 
C.  Frankel  prep.  (Kolle  and  Wassermann). 


especially  those  who  handle  hides  or  whose  occupation 
brings  them  into  contact  with  animals,  are  occasionally 
infected,  usually  in  the  form  of  "malignant  pustule." 
Among  wool-sorters  a  very  fatal  pulmonic  type  of  infec- 
tion is  observed.  Recently  it  has  been  charged  that  the 
disease  is  apt  to  be  spread  through  the  wearing  of  furs. 
This  is  unwarranted,  as  such  a  mode  of  infection  must  be 
extremely  rare.  Prophylaxis:  The  disease  in  cattle  and 
sheep  is  combated  by  means  of  immunizing  injections  of 


OTHER  IMPORTANT  PATHOGENIC  MICRO-ORGANISMS      175 

anthrax  vaccine,    Care  should  be  taken  to  properly  dis- 
pose of  the  carcass  of  any  animal  dead  of  anthrax. 

Malignant  Edema  Bacillus. — A  fairly  long,  thick  rod 
with  square  ends,  Gram-negative,  and  forming  spores. 
It  is  a  strict  anaerobe.  The  infections  in  man  are  usually 
the  result  of  infecting  wounds  with  garden  earth.  Pro- 


Fig.  59. — Bacillus  of  malignant  edema.  Tissue  juice  of  guinea- 
pig  after  injection  with  a  broth  culture.  Smear  preparation,  stained 
with  fuchsin.  X  1000  (Frankel  and  Pfeiffer). 

phylaxis:  The  careful  cleansing  of  all  wounds,  especially 
those  thought  to  be  infected  with  earth.. 

Typhus  Fever. — The  causative  organism,  Bacillus  typhi 
exanthematici,  has  recently  been  isolated  in  pure  culture 
by  Plotz,  working  in  the  laboratory  of  Mt.  Sinai  Hospital, 
New  York.  The  organism  is  a  small,  pleomorphic,  Gram- 
positive,  anaerobic,  non-motile,  and  non-acid-fast  bacillus. 
Most  of  the  organisms  are  straight:  occasionally  some  are 


176  APPLIED   BACTERIOLOGY  FOR   NURSES 

slightly  curved.  Coccoid  forms  occur.  The  bacilli  are 
most  abundant  in  the  blood  on  the  fourth  or  fifth  day 
preceding  the  crisis. 

Plotz  has  prepared  a  vaccine  from  this  organism,  but  the 
experience  with  this  is  still  too  short  to  determine  its  value 
in  combating  typhus  fever.  Infection  is  carried  from 


Fig.  60. — Bacillus  typhi  exanthematici.     Gram's  stain.    X    1000. 
(Plotz,  Olitsky,  and  Baehr,  in  Journal  of  Infectious  Diseases.) 

man  to  man  through  the  bite  of  infected  body  lice,  and 
perhaps  also  other  vermin.  Prophylaxis:  Cleanliness;  dis- 
infection of  infected  clothing;  measures  directed  against 
vermin. 

Leprosy  Bacillus. — Small,  acid-fast  rods,  resembling 
tubercle  .bacilli,  found  in  large  numbers,  especially  in  the 
cutaneous  lesions.  It  is  not  yet  established  just  how  the 
disease  is  communicated, 


OTHER  IMPORTANT  PATHOGENIC  MICRO-ORGANISMS      177 


Fig.  61. — Pure  culture  of  bacillus  of  leprosy,  showing  the  character- 
istic morphology  and  arrangement  of  the  bacilli  (Duval) . 


Fig.  62. — Microsporon  furfur,  fungus  of  pityriasis  versicolor;  X  700 

(Kaposi). 
12 


178 


APPLIED    BACTERIOLOGY   FOR   NURSES 


Microsporon  Furfur. — This  is  a  mold  producing  in  man 
the  skin  disease  known  as  "pityriasis."  It  is  observed 
chiefly  in  persons  living  under  conditions  of  uncleanli- 


Fig.  63.— Oidium  (Kolle  and  Wassermann). 


Fig.  64. — Achorion  schonleinii,  section  showing  the  hyphae  (Frankel 
and  Pfeiffer). 


OTHER  IMPORTANT  PATHOGENIC  MICRO-ORGANISMS      179 


ness  or  among  those  who  combine  these  conditions  with 
a  tendency  to  profuse  perspiration. 

Oidium  Albicans. — This  is  a  mold  producing  in  chil- 
dren the  disease  of  the  mouth 
known  as  "soor"  or  "thrush." 

Achorion  Schonleinii. — This 
is  a  mold  producing  the  dis- 
ease known  .as  "favus,"  is  an 
affection  of  the  scalp,  which 
runs  an  extremely  chronic 
course. 

Trichophyton  Tonsurans.— 
This  is  a  mold  producing 
the  disease  in  man  known  as 
"ring- worm." 

Poliomyelitis. — The  infect- 
ing microorganism  of  this 


m 


fttfJl 
m:i\ 


L.      ;.«£&MBL 

Fig.    65. — Invasion 


of 


disease  has  not  yet  been  iso-    human  hair  by  trichophy- 
lated,  but  is  known  to  exist 
the    nasal    secretion    and 


ton:  A,  Points  at  which  the 
parasitic  fungi  coming  from 
the  epidermis  are  elevating 
the  cuticle  of  the  hair  and 

in*°  its  ^bstance; 

(Sabouraud). 


in 

blood  of  infected  individuals. 

It  must  be  very  small,  for  it 

passes  through  the  pores  of  a 

Berkefeld  filter.    The  disease  is  said  to  be  transmitted 

through  the  bite   of   stable   flies,  but  probably  mainly 

through  infected  nasal  discharges. 


INDEX 


ABSCESS,  51 

stitch,  110 

Achorion  schoenleinii,  179 
Acid;  effect  of,  on  stained  bac- 
teria, 26 

formed  by  bacteria,  35 
Acid-fast,  definition  of,  26,  77 
Aerobic  bacteria,  definition  of,  20 
Agglutination  of  typhoid  bacilli, 

70 

Agglutinin,  nature  of,  69 
Alcohol,  effect  of,  on  leukocytes, 

66 
Anaerobic  bacteria,  definition  of, 

20 

Anaphylaxis,  nature  of,  74 
Animal  parasites,  148 
Anopheles  in  malaria,  57,  126 
Anthrax,  bacillus  of,  174 

immunity  of  dogs  to,  63 

through  food,  140 
Antibodies    as    defence    against 

bacteria,  66 

Antimeningococcus  serum,  113 
Antiseptic  surgery,  Lister's,  12 
Antiseptics,  effect  of,  on  bacteria, 

36 

Antistreptococcus  serum,   107 
Antitoxin  of  diphtheria,  97 

of  tetanus,  101 

Antitoxins,  nature  and  role  of,  66 
Arnold  steam  sterilizer,  44 

sterilizer  for  milk,  132 


Autoclave,  45,  155 
Autopsies,  collection  of  material 
from,  166 

BACILLUS  boltulinus,  139 

coli,  168 

definition  of,  15 

enteritidis,  139 

grip,  169 

mallei,  172 

of  anthrax,  174 

of  blue  pus,  171 

of  diphtheria,  93 

of  dysentery,  84 

of  glanders,  172 

of  influenza,  169 

of  lactic  acid,  136 

of  leprosy,  176 

of  malignant  edema,  175 

of  paratyphoid  fever,  169 

of  plague,  173 

of  pneumonia,  169 

of  scarlet  fever,  120 

of  tetanus,  99 

of  tuberculosis,  89 

of  typhoid  fever,  79 

of  typhus  fever,  175 

pestis,  173 

proteus  vulgaris,  140 

pyocyaneus,  171 

typhi  exanthematici,  175 
Bacteria,  character  of,  14 

cultivation  of,  27 

181 


182 


INDEX 


Bacteria,  definition  of,  13,  14 

effect     of     disinfectants     and 

antiseptics  on,  36 
of  heat  and  cold  on,  36 

important  pathogenic  species, 
48 

in  food  poisoning,  139 

in  milk,  130 

incubation  of,  29 

methods  of  studying,  22 

motility,  17 

relation  of,  to  destructive  in- 
fluences, 36 
to  disease,  47 

spore  formation,  17 

staining  of,  25 
Bacterial  vaccines,  77 
Bactericidal  serum,  68 
Bacteriology,  definition  of,  13 

historic,  11 
Bacteriolysins,  nature  and  role  of, 

67 
Behring,  discovery  of  diphtheria 

antitoxin,  95 
Bichlorid  of  mercury,  effect  of,  on 

bacteria,  37 

Blood,  defensive  role  of  blood- 
serum,  65 

parasite  of  malaria  in,  126 
Blood-stains,  test  for,  74 
Blown  cans,  141 

Boiling  water  for  disinfection,  150 
Boils,  treatment,  with  bacterial 

vaccines,  78,  111 
Bronchopneumonia,  103 
Budding,  definition  of,  13 

CALMETTE   test  for  tuberculous 

infection,  92 

Cancer,  relation  of  bacteria  to,  48 
Carbolic  acid,  effect  of,  on  bac- 
teria, 38 


Carriers  in  the  transmission  of 
disease,  55 

Cellulitis,  51 

Chancre  in  syphilis,  117 

Chicken-pox,  quarantine  in,  62 

Chickens,  immunity  to  tetanus, 
63 

Chlorid  of  lime,  effect  of,  on  bac- 
teria, 39 

Chlorin  in  disinfection  of  water, 
39,  145 

Cholera,  bacteriology  of,  86 
carried  by  water,  143 
quarantine  in,  62 
spirillum,  86 
treatment  of,  77 

Coccus,  definition  of,  15 

Cold,  effect  of,  on  bacteria,  36 
on  leukocytes,  66 

Coley's  mixed  toxins  for  sarcoma, 
108 

Colon  bacillus,  168 

in  food  poisoning,  140 
in  sanitary  water  examina- 
tions, 147 

Colostrum,  role  of,  in  transmis- 
sion of  immunity,  64 

Complement,  role  of,  69 

Cow-pox,  122 

Creolin,  effect  of,  on  bacteria,  38 

Culex  in  relation  to  malaria,  57 

Cultures,  method  of  making,  27 

Cytolysin,  nature  of,  68 

DAKIN'S  solution,  41 
Davaine,  anthrax  discoveries,  11 
Dengue,  virus  of,  125 
Diphtheria  antitoxin,  97 

bacillus,  93 

bacteriology  of,  93 

quarantine  in,  60 

Schick  test,  98 


INDEX 


183 


Diphtheria,  serum  treatment,  77 

throat  smears  in,  95,  166 

toxin,  96 

Diplococci,  definition  of,  16 
Diplococcus  of  gonorrhea,  115 

of  meningitis,  112 

of  pneumonia,  102 
Disease,  relation  of  bacteria  to, 
47 

transmission  of  infectious,  54 
Disinfectants,  effect  of,  on  bac- 
teria, 36 

testing  of,  41 

Disinfection   in    contagious   dis- 
eases, 160 

practice  of,  150 
Dry  heat  for  sterilization,  42 
Drying,  effect  of,  on  bacteria,  36 
Dysentery,  amebic,  84 

bacillus  of,  84 

bacteriology  of,  84 

EMPYEMA,  52 

Epidemic  cerebrospinal  meningi- 
tis, 112 

quarantine  in,  61 
serum  and  vaccines  in,  77 
Estivo-autumnal  malaria,   para- 
site of,  127 

Exanthemata,     bacteriology    of, 
120 

FAMULENER  on  transmission  of 

immunity,  64 
Favus,  179 

Feces,  collection  of,  167 
Fermentation  tube,  34 
Fermented  milk,  bacteriology  of, 

136 

Fermilac,  bacteriology  of,  138 
Filaria,  149 
Filterable  viruses,  124 


Filters,  bacterial,  124 

domestic,  144 
Fire  for  sterilization,  42 
Fishing  for  pure  cultures,  34 
Fixing  of  microscopic  smears,  25 
Flagella  in  motile  bacteria,  17 
Flies  as  carriers  of  infection,  57, 
135 

in  relation  to  poliomyelitis,  179 

to  typhoid  fever,  80 
Fomites  as  carriers  of  disease,  54 
Food  poisoning,  bacterial,  139 
Foot-and-mouth  disease,  virus  of, 

125 

Formaldehyd,  effect  of  bacteria 
on,  40 

for  fumigation,  163 
Freeman's  pasteurizer  for  milk, 

132 

Friedlander's   bacillus   of   pneu- 
monia, 169 

Fumigation  after  infectious  dis- 
eases, 56 

terminal,  56 

to  kill  vermin,  163,  164 

with  sulphur,  39 
Fungi,  definition  of,  13 

GARTNER'S  bacillus  in  food  poi- 
soning, 139 

Gas,  formation  of,  by  bacteria, 
34 

Gastric  juice,   role  of,   in  com- 
bating bacteria,  65 

German  measles,  121 
quarantine  in,  62 

Glanders,  bacillus  of,  172 

Goats,  immunity  to  tuberculosis, 
63 

Gonococcus,  115 

Gonorrhea,  bacteriology  of,  115 
vaccine  treatment  of,  116 


184 


INDEX 


Gram's  stain,  26 
Grip,  bacillus  of,  169 

HEAT,  destructive  effect  of,  on 
bacteria,  36 

in  cultivation  of  bacteria,  31 

sterilization  by,  42 

to  fix  bacteria,  25 
Hemameba  malariae,  126 
Hip  disease,  90 
Hog  cholera,  virus  of,  125 
Hookworm,  149 
Horses  for  antitoxin,  96 
Hot  air,  sterilizing  with,  42 
Hydrocephalus,  90 
Hydrogen  peroxid,  effect  of,  on 

bacteria,  40 
Hydrophobia,  virus  of,  125 

IMMUNITY,  definition  of,  63 

kinds  of,  63 

maternal  transmission  of,  64 
Immunizing  against  diphtheria, 

98 

Incubator  for  bacteria,  29 
Infantile  paralysis,  179.    See  also 

Poliomyelitis. 
Infectious  disease,  definition  of, 

12 

fumigation  after,  56 
quarantine  against,  59 
Infiltration,  purulent,  51 
Inflammation,  49 
Influenza  bacillus,  169 

serum  and  vaccines  in,  78 
Insects  as  carriers  of  infectious 

diseases,  56 
lodin  as  disinfectant,  40 

JENNER,    introduction    of    vac- 
cination, 123 


KOCH,  early  work  in  bacteriology, 

12 
Kumyss,  bacteriology  of,  137 

LACTATION  in  relation  to  trans- 
mission of  immunity,  64 

Lactic  acid  bacilli  in  milk,  136 

Laveran,   discoverer  of  malaria 
parasite,  126 

Lazy-worm,  149 

Leeuwenhoek,  discoverer  of  bac- 
teria, 11 

Leprosy,  bacillus  of,  176 

Leukocytes,  defensive  role  of,  65 

Lice  in  transmission  of  disease,  55 
relation  of,  to  typhus  fever,  176 

Light,  influence  of,  on  bacteria, 
19 

Lime,  chlorid  of,  as  disinfectant, 

39,  145 

freshly  slaked,  as  disinfectant, 
39 

Liquid  air,  effect  of,  on  bacteria, 
36 

Lister,  antiseptic  surgery,  12 

Litmus  to  study  acid  formation, 
35 

Lobar  pneumonia,  103 

Lockjaw,  99.    See  also  Tetanus. 

Lysol,  effect  of,  on  bacteria,  38 

MALARIA,  parasites  of,  126 

transmission  of,  57,  126 
Malignant  edema,  bacillus  of,  175 

pustule,  174 
Mallein  in  diagnosis  of  glanders, 

173 
Mallory,  observations  in  scarlet 

fever,  120 

Malta  fever,  micrococcus  of,  170 
Matzoon,  bacteriology  of,  138 
Measles,  quarantine  in,  60 


INDEX 


185 


Measles,  virus  of,  121 
Meningitis,  bacteriology  of,  112 

quarantine  in,  61 

treatment  with  serum,  113 
Meningococcus,  112 
Mercuric   chlorid,   effect   of,    on 

bacteria,  37 
Metschnikoff    fermented    milks, 

136 

Microbe,  definition  of,  13 
Micrococcus  of  Malta  fever,  170 
Microscope,  bacteriologic,  22 
Microsporon  furfur,  178 
Milk  as  carrier  of  disease,  134 

bacteriology  of,  130 

collection  of,  for  examination, 
166 

fermented,  bacteriology  of,  136 

grading,  130 

in    transmission     of    typhoid 
fever,  80,  134 

pasteurization  of,  131,  132 

streptococci  in,  134 

tubercle  bacilli  in,  89,  134 
Molds  pathogenic  for  man,  178 
Mordants  in  staining,  25 
Moro's  test  for  tuberculous  infec- 
tion, 92 
Moser's  antistreptococcus  serum, 

107 
Mosquitoes  in  malaria,  126 

in  yellow  fever,  128 
Motility  of  bacteria,  17 
Mucous  membrane,  protection  af- 
forded against  bacteria  by,  65 

patches  in  syphilis,  117 
Mumps,  quarantine  in,  62 

NEGRI  bodies  in  hydrophobia,  125 
Nicoll,  treatment  of  tetanus,  101 
Novy  jars  for  anaerobic  bacteria, 
20 


OIDIUM  albicans,  179 

Oil -immersion  objective,  23 

Opsonic  index,  73 

Opsonin,  nature  of,  72 

Oxygen,  influence  of,  on  growth 

of  bacteria,  20 
Oysters  in  typhoid  fever,  80 

PARATYPHOID  bacillus,  169 
Park,  diphtheria  immunity,  98 
Parotitis,  quarantine  in,  62 
Pasteurization,  definition  of,  36 

of  milk,  131,  132 
Pasteur's  early  work    in   bacte- 
riology, 12 

treatment  of  rabies,  78 
Pathogenic  bacteria,  definition  of, 

18 
Patient,  disinfection  of,  prior  to 

operation,  158 

Pellagra  not  a  germ  disease,  49 
Peroxid  of  hydrogen,  effect  of,  on 

bacteria,  40 
Pertussis,  170 

quarantine  in,  62 

vaccines  in,  78 
Pest,  bacillus  of,  173 
Petri  dishes  for  cultures,  32 
Peyer's  patches,  51 
Phenol,  effect  of,  on  bacteria,  38 
Pityriasis,  178 
Plague,  bacillus  of,  173 

vaccines  in,  77 
Plasmodium  malarise,  126 
Plates  for  growing  bacteria,  32 
Pleurisy,  dry,  52 
Plotz  on  typhus  fever,  175 
Pneumobacillus,      Friedlander's, 

169 

Pneumococcus,  102 
Pneumonia,  bacteriology  of,  103 

lobar,  103 


186 


INDEX 


Pneumonia,  serum  and  vaccine 

treatment,  77 
Poliomyelitis,  179 

mode  of  transmission,  179 

quarantine  in,  61 

virus  of,  125 
Pott's  disease,  90 
Precipitins,  nature  of,  73 
Pressure,  steam,  in  sterilizing,  46 
Protozoa,  definition  of,  13 

in  certain  diseases,  126 
Purulent  infiltration,  51 
Pyocyaneus,  bacillus  of,  171 

QUARANTINE  in  control  of  infec- 
tious diseases,  59 

Quartan  malaria,  parasite  of,  127 

Quicklime,  effect  of,  on  bacteria, 
39 

Quinin  in  malaria,  128 

RABIES,  treatment  of,  78 

virus  of,  125 

Rags  as  vehicles  of  infection,  55 
Rashes  after  serum  injections,  74 
Rats,  destruction  of,  by  sulphur 
fumigation,  40 

in  spread  of  plague,  173 
Rheumatism,  bacteriology  of,  49 
Rinderpest,  virus  of,  125 
Rose  spots  in  typhoid  fever,  79 

SARCOMA,  mixed  toxins  for,  108 
Scarlet  fever  and  antistreptococ- 

cus  serum,  107 
quarantine  in,  60 
virus  of,  120 
Schick  reaction,  98 
Serum  therapy,  75 
Skin  as  protection  against  bac- 
teria, 65 
Sleeping  sickness,  129 


Small-pox,  122 
quarantine  in,  61 

Snuffles  in  syphilis,  118 

Soor,  179 

Sour  milk,  bacteriology  of,  136 

Spirilla,  definition  of,  15 

Spirillum  of  cholera,  86 

Spores,  character  of,  16 

Sputum,  collection  of,  for  exam- 
ination, 165 

Squirrels  in  spread  of  plague,  173 

Staining  of  bacteria,  25 

Staphylococcus,  definition  of,  15 
pyogenes,  109 

Steam,  effect  of,  on  bacteria,  43 
for  disinfection,  46 
for  sterilization,  43,  153 

Stegomyia  in  relation  to  yellow 
fever,  128 

Sterilization  by  heat,  42 
by  steam,  43,  153 
of  instruments,  etc.,  151 
with  chemicals,  157 

Stitch  abscess,  110 

Stools,  collection  of,  167 
disinfection  of,  38,  39 

Streptococci  in  milk,  134 

Streptococcus,  definition  of,  15 
hemolyzing,  106 
infections,  serum  or  vaccines 

in,  78 
pyogenes,  105 

Sulphur  for  fumigation,  40,  162 

Sunlight,   influence  of,   on  bac- 
teria, 19 

Swelled  head,  141 

Syphilis,  bacteriology  of,  117 
Wassermann  test  in,  119 

TAPEWORMS,  148 
Temperature,    influence    of,    on 
growth  of  bacteria,  19 


INDEX 


1&7 


Terminal  fumigation,  56 
Tetanus  antitoxin,  101 
bacillus,  99 
bacteriology  of,  99 
serum  treatment,  77 
toxin,  100 

Tetrads,  definition  of,  16 
Throat  smears,  collection  of,  for 

examination,  95,  166 
Thrush,  179 
Toxin  of  diphtheria,  96 
Transmission   of   infectious   dis- 
eases, 54 
Treponema   pallida   in   syphilis, 

117 

Trichina,  148 

Trichophyton  tonsurans,  179 
Tricresol,  effect  of,  on  bacteria, 

38 

Trypanosomiasis,  129 
Tsetse    fly    in    transmission    of 

sleeping  sickness,  57,  129 
Tubercle  bacillus,  89 
Tuberculin,    diagnostic    use    of, 

91 

nature  of,  91 

Tuberculosis,  bacteriology  of,  89 
disinfection  in,  161 
immunity  of  goats  to,  63 
serum  and  vaccine  treatment, 

77 

tests  for,  91,  92 
Typhoid  fever,   bacteriology  of, 

79 

quarantine  in,  60 
use  of  vaccination  against, 

77,  83 
stools,  the  disinfection  of,  81, 

82 

Typhus  fever,  175 
quarantine  in,  61 
vaccines  in,  78 


ULTRAMICROSCOPE  in  diagnosis  of 
syphilis,  117 

Urine,  collection  of  sterile  speci- 
mens, 167 

VACCINATION  against  small-pox, 
123 

Vaccine,    collecting,    from    calf, 

122 
therapy,  75 

Vaccines,  bacterial,  77 
in  treatment  of  boils,  111 
of  gonococcus  infections,  111 

Vaccinia,  122 

Varicella,  quarantine  in,  62 

Variola,  122 

quarantine  in,  61 

Vermin,  sulphur  fumigation  in, 
40 

von  Pirquet's  test  for  tubercu- 
lous infection,  92 

WASSERMANN  test  for   syphilis, 

119 
Water,  bacteriologic  examination 

of,  142,  146 
collection  of,  for  examination, 

166 

disinfection  of,  39,  145 
nitration  of,  144 
in  transmission  of  cholera,  86, 

143 

of  typhoid  fever,  85,  143 
purification  of,  by  boiling,  146 
by  chlorination,  145 
by  distillation,  146 
natural,  143 

Water-borne  diseases,  143 
Whooping-cough,  170 

quarantine  in,  62 
Widal  reaction  in  typhoid  fever, 
82 


188 


INDEX 


Widal  reaction,  nature  of,  71 
Wool-sorters'  disease,  174 
Wright's   investigations   on   op- 
sonins,  72 


YEAST,  definition  of,  13 
in  fermenting  milk,  137 


Yellow  fever,  quarantine  in,  61 

transmission  of,  57 

virus  of,  125,  128 
Yoghurt,  bacteriology  of,  138 

ZINGHER,   diphtheria  immunity, 

98 
Zoolak,  bacteriology  of,  138 


Stoney's  Nursing 


NEW  (5th)  EDITION 


Of  this  work  the  American  Journal  of  Nursing  says:  ''It  is  the 
fullest  and  most  complete  and  may  well  be  recommended  as 
being  of  great  general  usefulness.  The  best  chapter  is  the  one 
on  observation  of  symptoms  which  is  very  thorough."  There 
are  directions  how  to  improvise  everything. 

Practical  Points  in  Nursing.  By  EMILY  M.  A.  STONEY.  Revised 
by  I,UCY  CORNELIA  CATLIN,  R.  N.,  Youngstown  Hospital,  Ohio. 
12mo.  511  pages,  illustrated.  Cloth,  $1.75  net.  Published  August.  1916 

Stoney's  Materia  Medica 

Stoney's  Materia  Medica  was  written  by  a  head  nurse  who 
knows  just  what  the  nurse  needs.  American  Medicine  says 
it  contains  "all  the  information  in  regards  to  drugs  that  a 
nurse  should  possess." 

Materia  Medica  for  Nurses.  By  EMILY  M.  A.  STONEY,  formerly  Super- 
intendent of  the  Training  School  for  Nurses  in  the  Carney  Hospital, 
South  Boston,  Mass,  New  (4th)  Edition  in  preparation. 


NEW  (4th)   EDITION 


Stoney's  Surgical  Technic 

The  first  part  deals  with  bacteriology,  including  antitoxins;  the 
second  with  all  the  latest  developments  in  surgical  technic. 
The  National  Hospital  Record  says:  "Pregnant  with  just  the 
information  nurses  constantly  need." 

Bacteriology  and  Surgical  Technic  for  Nurses.  By  EMILY  M.  A. 
STONEY.  342  pages,  illustrated.  Cloth,  $1.75  net.  October,  1916 

Goodnow's  First-Year  Nursing    2d  EDITION 

Miss  Goodnow's  work  deals  entirely  with  the  practical  side  of 
first-year  nursing  work.  It  is  the  application  of  text-book 
knowledge.  It  tells  the  nurse  how  to  do  those  things  she  is  called 
upon  to  do  in  her  first  year  in  the  training  school — the  actual 
ward  work. 

First-Year  Nursing.  By  MINNIE  GOODNOW,  R.  N.,  formerly  Super- 
intendent of  the  Women's  Hospital,  Denver.  12mo  of  354  pages, 
illustrated.  Cloth.  $1.50  net.  .  Published  February.  1916 


Aikens'  Hospital  Management 

This  is  just  the  work  for  hospital  superintendents,  training- 
school  principals,  physicians,  and  all  who  are  actively  inter- 
ested in  hospital  administration.  The  Medical  Record  says: 
'  'Tells  in  concise  form  exactly  what  a  hospital  should  do 
and  how  it  should  be  run,  from  the  scrubwoman  up  to  its 
financing." 

Hospital  Management.  Arranged  and  edited  by  CHARLOTTE  A. 
AIKENS,  formerly  Director  of  Sibley  Memorial  Hospital,  Washing- 
ton, D.  C.  488  pages,  illustrated.  Cloth,  $3.00  net.  April,  1911 

Aikens'  Primary  Studies          NEW  (3d)  EDITION 

Trained  Nurse  and  Hospital  Review  says:  *'  It  is  safe  to  say 
that  any  pupil  who  has  mastered  even  the  major  portion  of 
this  work  would  be  one  of  the  best  prepared  first  year  pupils 
who  ever  stood  for  examination." 

Primary  Studies  for  Nurses.  By  CHARLOTTE  A.  AIKENS,  formerly 
Director  of  Sibley  Memorial  Hospital,  Washington,  D.  C.  12mo  of 
472  pages,  illustrated.  Cloth,  $1.75  net.  Published  June,  1915 

Aikens'  Training-School  Methods  and 
the  Head  Nurse 

This  work  npt  only  tells  how  to  teach,  but  also  what  should 
be  taught  the  nurse  and  how  much.  The  Medical  Record  says: 
"  This  book  is  original,  breezy  and  healthy." 

Hospital  Training-School  Methods  and  the  Head  Nurse.  By  CHAR- 
LOTTE A.  AIKENS,  formerly  Director  of  Sibley  Memorial  Hospital, 
Washington,  D.  C.  267  pages.  Cloth,  $1.50  net.  October,  1907 

Aikens'    Clinical    Studies       NEW  (3d)  ED1TION 

This  work  for  second  and  third  year  students  is  written  on  the 
same  lines  as  the  author's  successful  work  for  primary  stu- 
dents. Dietetic  and  Hygienic  Gazette  says  there  "is  a  large 
amount  of  practical  information  in  this  book." 

Clinical  Studies  for  Nurses.  By  CHARLOTTE  A.  AIKENS,  formerly 
Director  of  Sibley  Memorial  Hospital,  Washington,  D.  C.  i2mo  of 
56g  pages,  illustrated  Cloth,  $2.00  net.  Published  August,  1916 


Bolduan  &  Grand's  Bacteriology  2d  EDITION 

The  authors  have  laid  particular  emphasis  on  the  immediate 
application  of  bacteriology  to  the  art  of  nursing.  It  is  an 
applied  bacteriology  in  the  truest  sense,  A  study  of  all  the 
ordinary  modes  of  transmission  of  infection  are  included. 

Applied  Bacteriology  for  Nurses.  By  CHARLES  F.  BOLDTJAN,  M.D., 
Director  Bureau  of  Public  Health  Education,  and  MARIE  GRUND. 
M.  D  ,  Bacteriologist,  Department  of  Health,  City  of  New  York 
188  pages,  illustrated.  Cloth,  $1.50  net.  Published  November,  1916 


Fiske's  The  Body 


A  NEW  IDEA 


Trained  Nurse  and  Hospital  Review  says  "it  is  concise,  well- 
written  and  well  illustrated,  and  should  meet  with  favor  in 
schools  for  nurses  and  with  the  graduate  nurse." 

Structure  and  Functions  of  the  Body.  By  ANNETTE  FISKE.  A.  M., 
Graduate  of  the  Waltham  Training  School  for  Nurses,  Massa- 
chusetts. i2mo  of  221  pages,  illustrated. Cloth,  $1.25  net.  May.  1911 

Beck's  Reference  Handbook     THIRD  EDITION 

This  book  contains  alt  the  information  that  a  nurse  requires 
to  carry  out  any  directions  given  by  the  physician.  The 
Montreal  Medical  Journal  says  it  is  ' '  cleverly  systematized  and 
Jiows  close  observation  of  the  sickroom  and  hospital  regime." 

A  Reference  Handbook  for  Nurses.  By  AMANDA  K.  BECK,  Graduate 
of  the  Illinois  Training  School  for  Nurses,  Chicago,  111.  32mo  of  244 
pages.  Bound  in  flexible  leather,  $1.25  net.  February,  1913 


NEW  (2d) 
EDITION 


Roberts'  Bacteriology  &  Pathology 

This  new  work  is  practical  in  the  strictest  sense.  Written 
specially  for  nurses,  it  confines  itself  to  information  that  the 
nurse  should  know.  All  unessential  matter  is  excluded.  The 
style  is  concise  and  to  the  point,  yet  clear  and  plain.  The  text 
is  illustrated  throughout. 

Bacteriology  and  Pathology  for  Nurses.  By  JAY  G.  ROBERTS,  Ph.  G., 
M.  D.,  Oskaloosa,  Iowa.    206  pages,  illus.    $1.50  net.         August,  1916 


DeLee's  Obstetrics  for  Nurses 

Dr.  DeL.ee' s  book  really  considers -two  subjects — obstetrics 
for  nurses  and  actual  obstetric  nursing.  Trained  Nurse  and 
Hospital  Review  says  the  ' '  book  abounds  with  practical 
suggestions,  and  they  are  given  with  such  clearness  that 
they  cannot  fail  to  leave  their  impress." 

Obstetrics  for  Nurses.  By  JOSEPH  B.  DEI^EE,  M.  D.,  Professor  of 
Obstetrics  at  the  Northwestern  University  Medical  School,  Chicago. 
12mo  volume  of  550  pages,  illustrated.  Cloth.  $2.75  net.  July.  1917 

Davis'  Obstetric  &  Gynecologic  Nursing 

JUST  OUT-NEW  (5th)  EDITION 

The  Trained  Nurse  and  Hospital  Review  says:  "  This  is  one 
of  the  most  practical  and  useful  books  ever  presented  to  the 
nursing  profession."  The  text  is  illustrated. 

Obstetric  and  Gynecologic  Nursing.  By  EDWARD  P.  DAVIS,  M.  D., 
Professor  of  Obstetrics  in  the  Jefferson  Medical  College,  Philadel- 
phia. 480  pages,  illustrated.  Cloth,  $2.00  net.  Published  May,  1917 

Macfarlane's  Gynecology  for  Nurses 

SECOND  EDITION 

Dr.  A.  M.  Seabrook,  Woman's  Hospital  of  Philadelphia,  says: 
''It  is  a  most  admirable  little  book,  covering  in  a  concise  but 
attractive  way  the  subject  from  the  nurse's  standpoint." 

A  Reference  Handbook  of  Gynecology  for  Nurses.  By  CATHARINE 
MACFARLANE,  M.  D.,  Gynecologist  to  the  Woman's  Hospital  of  Phila- 
delphia. 32010  of  156  pages,  with  70  illustrations.  Flexible  leather. 
$1.25  net  Published  May.  1913 

Asher's  Chemistry  and  Toxicology 

Dr.  Asher's  one  aim  was  to  emphasize  throughout  his  book 
the  application  of  chemical  and  toxicologic  knowledge  in  the 
study  and  practice  of  nursing.  He  has  admirably  succeeded. 

i2mo  of  190  pages.  By  PHILIP  ASHER.  PH.  G.,  M.  D.,  Dean  and  Pro- 
fessor of  Chemistry,  New  Orleans  College  of  Pharmacy.  Cloth, 
$1.25  net.  Published  October,  1914 


Aikens'  Home  Nurse's  Handbook 

The  point  about  this  work  is  this:  It  tells  you,  and  shows  you 
just  how  to  do  those  little  things  entirely  omitted  from  other 
nursing  books,  or  at  best  only  incidentally  treated.  The 
chapters  on  "Home  Treatments"  and  "Every-Day  Care  of 
the  Baby,"  stand  out  as  particularly  practical. 

Home  Nurse's  Handbook.  By  CHARLOTTE  A.  AIKENS,  formerly  Di- 
rector of  the  Sibley  Memorial  Hospital,  Washington,  D.  C.  i2mo  of 
303  pages,  illustrated.  Cloth.  $1.50  net.  Published  March.  1917 

Eye,  Ear,  Nose,  and  Throat  Nursing 

This  book  is  written  from  beginning  to  va&forthe  nurse.  You 
get  antiseptics,  sterilization,  nurse's  duties,  etc.  You  get  an- 
atomy and  physiology,  common  remedies,  how  to  invert  the 
lids,  administer  drops,  solutions,  salves,  anesthetics,  the 
various  diseases  and  their  management.  New  {2<T)  Edition. 

Nursing  in  Diseases  of  the  Eye,  Ear,  Nose  and  Throat.  By  the 
Committee  on  Nurses  of  the  Manhattan  Eye,  Ear  and  Throat  Hospital. 
iamo  of  291  pages,  illustrated.  Cloth,  $1.50  net.  Published  Sept.  1915 

Paul's  Materia  Medica  NEW  0,0  EDITION 

In  this  work  you  get  definitions — what  an  alkaloid  is,  an  in- 
fusion, a  mixture,  an  ointment,  a  solution,  a  tincture,  etc. 
Then  a  classification  of  drugs  according  to  their  physiologic 
action,  when  to  administer  drugs,  how  to  administer  them, 
and  how  much  to  give. 

A  Text-Book  of  Materia  Medica  for  Nurses.  By  GEORGE  P.  PAUL,  M.D. 
12mo  of  295  pages.  Cloth,  $1.50  net.  Published  August,  191  7 

Paul's  Fever  Nursing  NEw  «,»  EDITION 

In  the  first  part  you  get  chapters  on  fever  in  general,  hygiene, 
diet,  methods  for  reducing  the  fever,  complications.  In  the 
second  part  each  infection  is  taken  up  in  detail.  In  the  third 
part  you  get  antitoxins  and  vaccines,  bacteria,  warnings  of 
the  full  dose  of  drugs,  poison  antidotes,  enemata,  etc. 

Nursing  in  the  Acute  Infectious 'Fevers.  By  GKORGK  P.  PAUL,  M.  D. 
12mo  of  275  pages,  illustrated.  Cloth,  $1.00  net.  October,  1915 


McCombs'  Diseases  of  Children  for  Nurses 

NEW  (3d)    EDITION 

Dr.  McCombs'  experience  in  lecturing  to  nurses  has  enabled 
him  to  emphasize  just  those  points  that  nurses  most  need  to  know. 
National  Hospital  Record  says:  "We  have  needed  a  good 
book  on  children's  diseases  and  this  volume  admirably  fills 
the  want."  The  nurse's  side  has  been  written  by  head 
nurses,  very  valuable  being  the  work  of  Miss  Jennie  Manly. 

Diseases  of  Children  for  Nurses.  By  ROBERT  S.  McCOMBS,  M.  D., 
Instructor  of  Nurses  at  the  Children's  Hospital  of  Philadelphia,  izmo 
of  509  pages,  illustrated.  Cloth,  $2.00  net.  Published  June,  1916 


NEW  (3d)  EDITION 


Wilson's  Obstetric  Nursing 

In  Dr.  Wilson's  work  the  entire  subject  is  covered  from  the 
beginning  of  pregnancy,  its  course,  signs,  labor,  its  actual 
accomplishment,  the  puerperium  and  care  of  the  infant. 
American  Journal  of  Obstetrics  says:  "  Every  page  empasizes 
the  nurse's  relation  to  the  case." 

A  Reference  Handbook  of  Obstetric  Nursing.  By  W.  REYNOLDS 
WILSON,  M.  D.,  Visiting  Physician  to  the  Philadelphia  I,ying-m 
Charity.  355  pages,  illus.  Flexible  leather,  $1.25  net.  April,  1916 

American  Pocket  Dictionary  NEW  uotn)  EDITION 

The  Trained  Nurse  and  Hospital  Review  says:  "We  have 
had  many  occasions  to  refer  to  this  dictionary,  and  in  every 
instance  we  have  found  the  desired  information. " 

American  Pocket  Medical  Dictionary.  Edited  by  W.  A.  NKWMAX 
BORLAND,  A.  M.,  M.  D.  Flexible  leather,  gold  edges,  $1.25  net; 
indexed,  $1.50  net.  Published  September,  1917 


Lewis'  Anatomy  and  Physiology 


THIRD 
EDITION 


Nurses  Journal  of  Pacific  Coast  says  ' '  it  is  not  in  any  sense 
rudimentary,  but  comprehensive  in  its  treatment  of  the  sub- 
jects. "  The  low  price  makes  this  book  particukrly  attractive. 

Anatomy  and  Physiology  for  Nurses.    By  I<EROY  I/rwis,  M.D.    12mo 
of  326  pages;    150  illustrations.     Cloth,  $1.75  net. 

Published  September.  1913 


Goodnow's  War  Nursing  JUST  OUT 

Written  at  the  front  and  on  the  battlefield,  this  book  shows  the 
inexperienced  nurse  how  to  care  for  a  ward  of  wounded  men 
from  arrival  to  dismissal;  it  introduces  you  to  actual  conditions, 
and  shows  you  how  they  are  best  met. 

War  Nursing:  a  Text-Book  for  Auxiliary  Nurses.  By  MINNIE  GOOD- 
NOW,  R.  N.,  War  Nurse  in  France.  172  pages,  illustrated.  Cloth. 
$1.50  net.  Published  December,  1917 

Warnshuis'  Surgical  Nursing 

The  author  gives  you  here  the  essential  principles  of  surgical 
nursing,  and  reliable  fundamental  knowledge  based  on  his 
own  personal  conclusions  and  experiences.  Secondary  matter 
is  excluded,  and  all  primary  and  pertinent  points  are  set  down 
briefly  and  concisely. 

Octavo  of  280  pages,  with  255  illustrations.  By  FREDERICK  C. 
WARNSHUIS,  M.D.,  F.A.C.S.,  Visiting  Surgeon,  Butterworth  Hos- 
pital, Grand  Rapids,  Michigan, 

Friedenwald  and  Ruhrah's  Dietetics  for 

IN  UrSeS  NEW  (4th)  EDITION 

This  work  has  been  prepared  to  meet  the  needs  of  the  nurse, 
both  in  training  school  and  after  graduation.  American  Jour- 
nal of  Nursing  says  it  "is  exactly  the  book  for  which  nurses 
and  others  have  long  and  vainly  sought." 

Dietetics  for  Nurses.  By  JULIUS  FRIEDENWALD,  M.  D.,  and  JOHN 
RUHRAH,  M.D.,  University  of  Maryland  School  of  Medicine  and 
College  of  Physicians  and  Surgeons,  Baltimore.  12mo  volume  of  467 
pages.  Cloth,  $1.50  net  Published  July,  1917 


FOURTH 
EDITION 


Friedenwald  &  Ruhrah  on  Diet 

This  work  is  a  fuller  treatment  of  the  subject  of  diet,  pre- 
sented along  the  same  lines  as  the  smaller  work.  Everything 
concerning  diets,  their  preparation  and  use,  coloric  values, 
rectal  feeding,  etc.,  is  here  given  in  the  light  of  the  most  re- 
cent researches.  Pubii.hed  July.  191? 

Diet  in  Health  and  Disease.     By  JULIUS   FRIEDENWALD.    M.D.,  and 
JOHN  RUHRAH,  M.D.    Octavo  volume  of  857  pages.     Cloth.  $4.00  net 


\   Personal    Hvoipnp  NEW  <?th)  EDITION 

^  i^ciMJiidi  nygiciic  published  August,  191? 

Dr.  Pyle's  work  discusses  the  care  of  the  teeth,  skin,  com- 
plexion and  hair,  bathing,  clothing,  mouth  breathing,  catch- 
ing cold;  singing,  care  of  the  eyes,  school  hygiene,  body 
posture,  ventilation,  heating,  water  supply,  house-cleaning, 
home  gymnastics,  first-aid  measures,  etc. 

A  Manual  of  Personal  Hygiene.  Edited  by  WALTER  I,.  PYLE,  M.  D., 
Wills  Eye  Hospital,  Philadelphia.  555  pages,  illus.  $1.75  net. 

Galbraith's  Personal  Hygiene  and  Physical 
Training  for  Women  NEW  (2d>  EDITION 

Dr.  Galbraith's  book  tells  you  how  to  train  the  physical  pow- 
ers to  their  highest  degree  of  efficiency  by  means  of  fresh  air, 
tonic  baths,  proper  food  and  clothing,  gymnastic  and  outdoor 
exercise.  There  are  chapters  on  the  skin,  hair,  development 
of  the  form,  carriage,  dancing,  walking,  running,  swimming, 
rowing,  and  other  outdoor  sports. 

Personal  Hygiene  and  Physical  Training  for  Women.  By  ANNA  M. 
GALBRAITH,  M.D.,  Fellow  New  York  Academy  of  Medicine.  izmo  of 
393  pages,  illustrated.  Cloth,  $2.25  net.  Published  January.  1917 

Galbraith's  Four  Epochs  of  Woman's  Life 

This  book  covers  each  epoch  fully,  in  a  clean,  instructive  way, 
taking  up  puberty,  menstruation,  marriage,  sexual  instinct, 
sterility,  pregnancy,  confinement,  nursing,  the  menopause. 

The  Four  Epochs  of  Women's  Life.  By  ANNA  M.  GALBRAITH,  M.D., 
with  an  Introductory  Note  by  JOHN  H.  MUSSER,  M.  D.  12mo  of  296 
pages.  Cloth,  $1.50  net.  Third  Edition  published  March,  1917 

Griffith's  Care  of  the  Baby     NEw  «*)  EDITION 


Here  is  a  book  that  tells  in  simple,  straightforward  language 
exactly  how  to  care  for  the  baby  in  health  and  disease  ;  how 
to  keep  it  well  and  strong;  and  should  it  fall  sick,  how  to 
carry  out  the  physician's  instructions  and  nurse  it  back  to 
health  again.  Published  June.  1915 

The  Care  of  the  Baby.     By  J.  P.  CROZER  GRIFFITH,  M.D.,  Univers- 
ity of  Pennsylvania,    izmo  of  458  pages,  illustrated.     Cloth,  $1.50  net 


Aikens'  Ethics  for  Nurses 

This  book  emphasizes  the  importance  of  ethical  training.  It 
is  a  most  excellent  text-book,  particularly  well  adapted  for 
classroom  work.  The  illustrations  and  practical  problems 
used  in  the  book  are  drawn  from  life. 

Studies  in  Ethics  for  Nurses.  By  CHARLOTTE  A.  AIKENS,  formerly 
Superintendent  of  Columbia  Hospital,  Pittsburg.  iamo  of  318  pages. 
Cloth.  $1.75  net.  Published  April.  1916 

Goodnow's  History  of  Nursing 

Miss  Goodnow's  work  gives  the  main  facts  of  nursing  history 
from  the  beginning  to  the  present  time.  It  is  suited  for  class- 
room work  or  postgraduate  reading.  Sufficient  details  and 
personalities  have  been  added  to  give  color  and  interest,  and 
to  present  a  picture  of  the  times  described. 

History  of  Nursing.  By  MINNIE  GOODNOW,  R.N.,  formerly  Super- 
intendent of  the  Women's  Hospital,  Denver.  i2mo  of  370  pages, 
illustrated.  Cloth,  $2.00  net.  Published  December,  1916 

Berry's  Orthopedics  for  Nurses 

The  object  of  Dr.  Berry's  book  is  to  supply  the  nurse  with  a 
work  that  discusses  clearly  and  simply  the  diagnosis,  prog- 
nosis and  treatment  of  the  more  common  and  important  ortho- 
pedic deformities.  Many  illustrations  are  included.  The 
work  is  very  practical. 

Or.hopedic  Surgery  for  Nurses.  By  JOHN  McWlLUAMS  BERRY. 
M.D.,  Clinical  Professor  of  Orthopedics  and  Rontgenology,  Albany 
Medical  College.  Cloth,  $1.00  net.  Published  July.  1916 

Whiting's  Bandaging 

This  new  work  takes  up  each  bandage  in  detail,  telling  you — 
and  showing  you  by  original  illustrations — just  how  each 
bandage  should  be  applied,  each  turn  made.  Dr.  Whiting's 
teaching  experience  has  enabled  him  to  devise  means  for  over- 
coming common  errors  in  applying  bandages. 

Bandaging.  By  A.  D.  WHITING,  M.D  ,  Instructor  in  Surgery  at  the 
University  of  Pennsylvania.  iamo  of  151  pages,  with  117  illustra- 
tions. Cloth,  $1.25  net.  Published  November.  1915 

10 


Smith's  Operating-Room 

The  object  is  to  show  you  how  to  assist  the  surgeon  according 
to  the  newest  operative  technic.  You  get  the  result  of  active 
experience  systematized,  and  in  concise  form.  You  get  a  thor- 
ough digest  of  every  essential ;  detailed  lists  of  instruments ; 
glossary  of  medical  terms.  Every  phase  of  the  subject  is 
covered  by  ample,  practical  instruction. 

The  Operating-Room.  A  Primer  for  Nurses.  By  AMY  ARMOUR 
SMITH,  R.N.,  formerly  Superintendent  of  Nurses  at  the  Woman's 
Hospital  of  the  State  of  New  York.  12mo  of  295  pages,  illustrated. 
Cloth,  $1.50  net.  Published  October,  1916 

Handler's  The  Expectant  Mother 

This  is  an  anatomy,  physiology  and  hygiene  covering  those 
points  and  functions  concerned  in  child-bearing  and  designed 
for  the  use  of  the  nurse  and  the  mother.  Every  question  of 
interest  to  the  expectant  mother  is  treated. 

The  Expectant  Mother.  By  S.  WYLLIS  HANDLER,  M.  D.,  Professor 
of  Diseases  of  Women,  New  York  Post-Graduate  Medical  School 
and  Hospital.  Cloth,  $1.25  net.  Published  October,  1916 

Winslow's  Prevention  of  Disease 

Here  you  get  a  practical  guide,  giving  you  briefly  the  means 
to  avoid  the  various  diseases  described.  The  chapters  on  diet, 
exercise,  tea,  coffee,  alcohol,  prevention  of  cancer,  etc.,  are  of 
special  interest.  There  are,  besides,  chapters  on  the  preven- 
tion of  malaria,  colds,  constipation,  obesity,  nervous  disorders 
and  tuberculosis.  It  is  a  record  of  twenty-five  years'  active 
practice. 

By  KENELM  WINSLOW,  M.D.,  formerly  Assistant  Professor  of  Com- 
parative Therapeutics,  Harvard  University.  12mo  of  348  pages, 
illustrated.  Cloth,  $1.75  net.  Published  November.  1916 

Brady's  Personal  Health 

This  is  different  from  other  health  books.  It  is  written  by  a 
physician  with  some  fifteen  years'  experience  in  writing  for  the 
laity.  It  covers  the  entire  range  of  health  questions — care  of 
mouth  and  teeth,  catching  cold,  adenoids  and  tonsils,  eye  and 
ear,  ventilation,  skin,  hair  and  .nails,  nutrition,  nervous  ail- 
ments, etc. 

Personal  Health.      A  Doctor  Book  for  Discriminating  People.     By 

WILLIAM  BRADY,  M.D.,  Elmira,  N.Y.    12mo  of  400  pages. 

Cloth,  $1.50  net.  Published  September.  1916 


Hoxie  &  Laptad's  Medicine  for  Nurses 

Medicine  for  Nurses  and  Housemothers.  By  GEORPE 
HOWARD  HOXIE,  M.  D.,  University  of  Kansas;  and 
PEARL  L.  LAPTAD.  12mo  of  351  pages,  illustrated. 
Cloth,  $1.50  net.  Second  Edition— April,  1913 

Bohm  &  Painter's  Massage 

Massage.  By  MAX  BOHM,  M.D.,  Berlin,  Germany.  -Ed- 
ited by  CITAS.  F.  PAINTER,  M.D. ,  Tufts  College.  Octavo 
of  91  pages,  97 illustrations.  Cloth,  $1.75  net.  June,  1913 

Boyd's  State  Registration  for  Nurses 

State  Registration  for  Nurses.  By  LOUIE  CROFT  BOYD, 
R.  N.,  Graduate  Colorado  Training  School  for  Nurses. 
Cloth,  $1.25  net.  Second  Edition— February,  1915 

Morrow's  Immediate  Care  of  Injured 

Immediate  Care  of  the  Injured.  By  ALBERTS.  MOR- 
ROW, M.D.,  New  York  Polyclinic.  Octavo  of  354  pages, 
with  242  illustrations.  Cloth,  $2.75  net. 

Third  Edition— November,  1917 


deNancrede's  Anatomy 


EIGHTH   EDITION 


Essentials  of  Anatomy.  By  CHARLES  B.  G.  DENAN- 
CREDE,  M.  D.,  University  of  Michigan.  12mo  of  400 
pages,  180  illustrations.  Cloth,  $1.25  net.  Sept.,  1911 


Morris'  Materia  Medica 


SEVENTH  EDITION 

Essentials  of  Materia  Medica,  Therapeutics,  and   Pre- 
scription Writing.      By  HENRY  MORRIS,  M.  D.       Re- 
vised by  W.  A.  BASTEDO,  M.  D.,  Columbia  University, 
New  York.     12mo  of  300  pages,  illustrated. 
Cloth,  $1.25  net.  Published  March,   1905 


Register's  Fever  Nursing 


A  Text-Book  on  Practical  Fever  Nursing.  By  EDWARD  C. 
REGISTER,  M.D. ,  North  Carolina  Medical  College.  Oc- 
tavo of  350  pages,  illustrated.  Cloth,  $2.50  net.  June  1907 


THIS  BOOK  IS  DUE  ON  **-*•.  T 


TY  OF  CALIFORNIA  LIBRARY 


